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Luo Y, Yang H, Ying C, Wang R, Bo Z, Yan J, Cen K, Ostrikov KK. Plasma-Activated Solutions Regulate Surface-Terminating Groups Enhancing Pseudocapacitive Ti 3 C 2 T x Electrode Performance. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2305383. [PMID: 37661349 DOI: 10.1002/smll.202305383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/09/2023] [Indexed: 09/05/2023]
Abstract
2D transition metal carbides and nitrides (MXenes) are actively pursued as pseudocapacitive materials for supercapacitors owing to their advantages in electronic conductivity and surface reactivity. Increasing the fraction of ─O terminal groups in Ti3 C2 Tx is a promising approach to improve the pseudocapacitive charge storage in H2 SO4 electrolytes, but it suffers from a lack of effective functionalization methods and stability of the groups in practical operation. Here a low-temperature and environment-friendly approach via the interaction of nonequilibrium plasmas with Ti3 C2 Tx dispersion is demonstrated to generate abundant and stable surface-terminating O groups. The impact of the discharge environment (Ar, O2 , and H2 ) on the structural characteristics and electrochemical performance of Ti3 C2 Tx nanosheets is studied. The Ti3 C2 Tx modified in Ar and H2 maintains their original morphology but a significantly lower F content. Consequently, an extraordinarily high content (78.5%) of surface-terminating O groups is revealed by the high-resolution X-ray photoelectron spectroscopy spectra for the Ti3 C2 Tx samples modified in H2 plasma-treated solutions. Additionally, the Ti3 C2 Tx treated using H2 plasmas exhibits the best capacitive performance of 418.3 F g-1 at 2 mV s-1 , which can maintain 95.88% capacity after 10 000 cycles. These results contribute to the development of advanced nanostructured pseudocapacitive electrode materials for renewable energy storage applications.
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Affiliation(s)
- Yonghong Luo
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Huachao Yang
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Chongyan Ying
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Rui Wang
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Zheng Bo
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jianhua Yan
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Kefa Cen
- State Key Laboratory of Clean Energy Utilization, College of Energy Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Kostya Ken Ostrikov
- School of Chemistry and Physics & Centre for Materials Science, Queensland University of Technology, Brisbane, Queensland, 4000, Australia
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2
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Liang C, Liu Z, Sun B, Zou H, Chu G. Improvement in Discharge Characteristics and Energy Yield of Ozone Generation via Configuration Optimization of a Coaxial Dielectric Barrier Discharge Reactor. Chin J Chem Eng 2023. [DOI: 10.1016/j.cjche.2022.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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3
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Zhou B, Qin L, Wang P, Chen Z, Zang J, Zhang J, Wen Y, Chen R. Fabrication of ZnO dual electron transport layer via atomic layer deposition for highly stable and efficient CsPbBr 3perovskite nanocrystals light-emitting diodes. NANOTECHNOLOGY 2022; 34:025203. [PMID: 36215973 DOI: 10.1088/1361-6528/ac98ce] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Electron transport layers (ETLs) are important components of high-performance all-inorganic perovskite nanocrystals light-emitting diodes (PNCs-LED). Herein, atomic layer deposition (ALD) of inorganic ZnO layer is combined to the organic 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) to form dual ETLs to enhance both the efficiency and stability of PNCs-LED simultaneously. Optimization of ZnO thickness suggested that 10 cycles ALD yields the best performance of the devices. The external quantum efficiency of the device reaches to 7.21% with a low turn-on voltage (2.4 V). Impressively, the dual ETL PNCs-LED realizes maximumT50lifetime of 761 h at the initial luminance of 100 nit, which is one of the top lifetimes among PNCs-LEDs up to now. The improved performance of dual ETL PNCs-LED is mainly due to the improved charge transport balance with favorable energy level matching. These findings present a promising strategy to modify the function layer via ALD to achieve both highly efficient and stable PNCs-LED.
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Affiliation(s)
- Binze Zhou
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China
| | - Le Qin
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China
| | - Pengfei Wang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, People's Republic of China
| | - Zhuo Chen
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, People's Republic of China
| | - Jianfeng Zang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, People's Republic of China
| | - Jianbing Zhang
- School of Optical and Electronic Information, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei, 430074, People's Republic of China
| | - Yanwei Wen
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China, Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen 518067, People's Republic of China
| | - Rong Chen
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China
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4
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He Y, Yi X, Zhang Z, Luo H, Li R, Feng X, Fang ZM, Zhu XH, Cheng W, Jiang DS, Zhao F, Wei X. JIB-04, a histone demethylase Jumonji C domain inhibitor, regulates phenotypic switching of vascular smooth muscle cells. Clin Epigenetics 2022; 14:101. [PMID: 35964071 PMCID: PMC9375951 DOI: 10.1186/s13148-022-01321-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/05/2022] [Indexed: 11/25/2022] Open
Abstract
Background Vascular smooth muscle cell (VSMC) phenotype switching is critical for neointima formation, which is the major cause of restenosis after stenting or coronary artery bypass grafting. However, the epigenetic mechanisms regulating phenotype switching of VSMCs, especially histone methylation, are not well understood. As a main component of histone lysine demethylases, Jumonji demethylases might be involved in VSMC phenotype switching and neointima formation. Methods and results A mouse carotid injury model and VSMC proliferation model were constructed to investigate the relationship between histone methylation of H3K36 (downstream target molecule of Jumonji demethylase) and neointima formation. We found that the methylation levels of H3K36 negatively correlated with VSMC proliferation and neointima formation. Next, we revealed that JIB-04 (a pan-inhibitor of the Jumonji demethylase superfamily) could increase the methylation levels of H3K36. Furthermore, we found that JIB-04 obviously inhibited HASMC proliferation, and a cell cycle assay showed that JIB-04 caused G2/M phase arrest in HASMCs by inhibiting the phosphorylation of RB and CDC2 and promoting the phosphorylation of CHK1. Moreover, JIB-04 inhibited the expression of MMP2 to suppress the migration of HASMCs and repressed the expression of contraction-related genes. RNA sequencing analysis showed that the biological processes associated with the cell cycle and autophagy were enriched by using Gene Ontology analysis after HASMCs were treated with JIB-04. Furthermore, we demonstrated that JIB-04 impairs autophagic flux by downregulating STX17 and RAB7 expression to inhibit the fusion of autophagosomes and lysosomes. Conclusion JIB-04 suppresses the proliferation, migration, and contractile phenotype of HASMCs by inhibiting autophagic flux, which indicates that JIB-04 is a promising reagent for the treatment of neointima formation. Supplementary Information The online version contains supplementary material available at 10.1186/s13148-022-01321-8.
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Affiliation(s)
- Yi He
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Xin Yi
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zihao Zhang
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Hanshen Luo
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Rui Li
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Xin Feng
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Ze-Min Fang
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China
| | - Xue-Hai Zhu
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation; Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, Hubei, China
| | - Wenlin Cheng
- Department of Cardiology, Zhongnan Hospital of Wuhan University, East Lake Road 169, Wuhan, Hubei, China.,Institute of Myocardial Injury and Repair, Wuhan University, Wuhan, Hubei, China
| | - Ding-Sheng Jiang
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China.,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation; Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, Hubei, China
| | - Fang Zhao
- Department of Cardiology, Zhongnan Hospital of Wuhan University, East Lake Road 169, Wuhan, Hubei, China. .,Institute of Myocardial Injury and Repair, Wuhan University, Wuhan, Hubei, China.
| | - Xiang Wei
- Division of Cardiothoracic and Vascular Surgery, Sino-Swiss Heart-Lung Transplantation Institute, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan, 430030, Hubei, China. .,Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation; Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Wuhan, Hubei, China.
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5
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Staller CM, Gibbs SL, Gan XY, Bender JT, Jarvis K, Ong GK, Milliron DJ. Contact Conductance Governs Metallicity in Conducting Metal Oxide Nanocrystal Films. NANO LETTERS 2022; 22:5009-5014. [PMID: 35640240 DOI: 10.1021/acs.nanolett.2c01852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although colloidal nanoparticles hold promise for fabricating electronic components, the properties of nanoparticle-derived materials can be unpredictable. Materials made from metallic nanocrystals exhibit a variety of transport behavior ranging from insulators, with internanocrystal contacts acting as electron transport bottlenecks, to conventional metals, where phonon scattering limits electron mobility. The insulator-metal transition (IMT) in nanocrystal films is thought to be determined by contact conductance. Meanwhile, criteria are lacking to predict the characteristic transport behavior of metallic nanocrystal films beyond this threshold. Using a library of transparent conducting tin-doped indium oxide nanocrystal films with varied electron concentration, size, and contact area, we assess the IMT as it depends on contact conductance and show how contact conductance is also key to predicting the temperature-dependence of conductivity in metallic films. The results establish a phase diagram for electron transport behavior that can guide the creation of metallic conducting materials from nanocrystal building blocks.
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Affiliation(s)
- Corey M Staller
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Stephen L Gibbs
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Xing Yee Gan
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jay T Bender
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Karalee Jarvis
- Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, United States
| | - Gary K Ong
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Delia J Milliron
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
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6
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Zhang C, Tu Q, Francis LF, Kortshagen UR. Band Gap Tuning of Films of Undoped ZnO Nanocrystals by Removal of Surface Groups. NANOMATERIALS 2022; 12:nano12030565. [PMID: 35159909 PMCID: PMC8838492 DOI: 10.3390/nano12030565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/24/2022] [Accepted: 02/02/2022] [Indexed: 11/16/2022]
Abstract
Transparent conductive oxides (TCOs) are widely used in optoelectronic devices such as flat-panel displays and solar cells. A significant optical property of TCOs is their band gap, which determines the spectral range of the transparency of the material. In this study, a tunable band gap range from 3.35 eV to 3.53 eV is achieved for zinc oxide (ZnO) nanocrystals (NCs) films synthesized by nonthermal plasmas through the removal of surface groups using atomic layer deposition (ALD) coating of Al2O3 and intense pulsed light (IPL) photo-doping. The Al2O3 coating is found to be necessary for band gap tuning, as it protects ZnO NCs from interactions with the ambient and prevents the formation of electron traps. With respect to the solar spectrum, the 0.18 eV band gap shift would allow ~4.1% more photons to pass through the transparent layer, for instance, into a CH3NH3PbX3 solar cell beneath. The mechanism of band gap tuning via photo-doping appears to be related to a combination of the Burstein–Moss (BM) and band gap renormalization (BGN) effects due to the significant number of electrons released from trap states after the removal of hydroxyl groups. The BM effect shifts the conduction band edge and enlarges the band gap, while the BGN effect narrows the band gap.
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Affiliation(s)
- Chengjian Zhang
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55414, USA; (C.Z.); (Q.T.)
| | - Qiaomiao Tu
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55414, USA; (C.Z.); (Q.T.)
| | - Lorraine F. Francis
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55414, USA; (C.Z.); (Q.T.)
- Correspondence: (L.F.F.); (U.R.K.)
| | - Uwe R. Kortshagen
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55414, USA
- Correspondence: (L.F.F.); (U.R.K.)
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7
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Ruiz-Garcia H, Ramirez-Loera C, Malouff TD, Seneviratne DS, Palmer JD, Trifiletti DM. Novel Strategies for Nanoparticle-Based Radiosensitization in Glioblastoma. Int J Mol Sci 2021; 22:9673. [PMID: 34575840 PMCID: PMC8465220 DOI: 10.3390/ijms22189673] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 01/09/2023] Open
Abstract
Radiotherapy (RT) is one of the cornerstones in the current treatment paradigm for glioblastoma (GBM). However, little has changed in the management of GBM since the establishment of the current protocol in 2005, and the prognosis remains grim. Radioresistance is one of the hallmarks for treatment failure, and different therapeutic strategies are aimed at overcoming it. Among these strategies, nanomedicine has advantages over conventional tumor therapeutics, including improvements in drug delivery and enhanced antitumor properties. Radiosensitizing strategies using nanoparticles (NP) are actively under study and hold promise to improve the treatment response. We aim to describe the basis of nanomedicine for GBM treatment, current evidence in radiosensitization efforts using nanoparticles, and novel strategies, such as preoperative radiation, that could be synergized with nanoradiosensitizers.
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Affiliation(s)
- Henry Ruiz-Garcia
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA; (H.R.-G.); (T.D.M.); (D.S.S.)
- Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL 32224, USA;
| | | | - Timothy D. Malouff
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA; (H.R.-G.); (T.D.M.); (D.S.S.)
| | - Danushka S. Seneviratne
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA; (H.R.-G.); (T.D.M.); (D.S.S.)
| | - Joshua D. Palmer
- Department of Radiation Oncology, Ohio State University, Columbus, OH 43210, USA;
| | - Daniel M. Trifiletti
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA; (H.R.-G.); (T.D.M.); (D.S.S.)
- Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL 32224, USA;
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8
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Cendejas AJ, Sun H, Hayes SE, Kortshagen U, Thimsen E. Predicting plasma conditions necessary for synthesis of γ-Al 2O 3 nanocrystals. NANOSCALE 2021; 13:11387-11395. [PMID: 34160531 DOI: 10.1039/d1nr02488d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nonthermal plasma (NTP) offers a unique synthesis environment capable of producing nanocrystals of high melting point materials at relatively low gas temperatures. Despite the rapidly growing material library accessible through NTP synthesis, designing processes for new materials is predominantly empirically driven. Here, we report on the synthesis of both amorphous alumina and γ-Al2O3 nanocrystals and present a simple particle heating model that is suitable for predicting the plasma power necessary for crystallization. The heating model only requires the composition, temperature, and pressure of the background gas along with the reactor geometry to calculate the temperature of particles suspended in the plasma as a function of applied power. Complete crystallization of the nanoparticle population was observed when applied power was greater than the threshold where the calculated particle temperature is equal to the crystallization temperature of amorphous alumina.
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Affiliation(s)
- Austin J Cendejas
- Department of Energy, Environmental and Chemical Engineering, Washington University in Saint Louis, Saint Louis, Missouri, USA.
| | - He Sun
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, Missouri, USA and Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri, USA
| | - Sophia E Hayes
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, Missouri, USA and Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri, USA
| | - Uwe Kortshagen
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Elijah Thimsen
- Department of Energy, Environmental and Chemical Engineering, Washington University in Saint Louis, Saint Louis, Missouri, USA. and Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri, USA
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9
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Di Trolio A, Testa AM, Amore Bonapasta A. Role of the carrier density in the transport mechanisms of polycrystalline ZnO films. Phys Chem Chem Phys 2021; 23:13918-13925. [PMID: 34132716 DOI: 10.1039/d1cp01612a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The transport processes occurring in polycrystalline ZnO have been investigated by measuring the resistivity as a function of temperature in ZnO films with different n-doping levels, obtained by varying the oxygen pressure during the deposition process. These films show an electrical resistivity spanning about two orders of magnitude, from 4 to 8 × 10-2Ω cm at room temperature, corresponding to low and high levels of n-type doping, respectively. The present results indicate a relevant role of the carrier density in determining the dominant transport mechanisms in these samples by showing that the picture characterizing a highly n-doped ZnO sample, where an intra-grain mechanism and a grain-boundary mechanism dominate the high temperature and low temperature transport processes, respectively, is thoroughly overturned in lightly n-doped samples, where a grain-boundary mechanism and an intra-grain mechanism govern the charge transport in the same temperature regimes, respectively. Moreover, the present results indicate a critical role of the conditions limiting the occurrence of the Mott variable range hopping regime. They show indeed that an incomplete check of such conditions can result in erroneous conclusions about the prevalent transport mechanisms.
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Affiliation(s)
- A Di Trolio
- CNR-Istituto di Struttura della Materia, Via del fosso del cavaliere 100, 00133 Roma, Italy.
| | - A M Testa
- CNR-Istituto di Struttura della Materia, U.O.S. di Monterotondo, Via Salaria Km. 29,300, 00015 Monterotondo St. (Roma), Italy
| | - A Amore Bonapasta
- CNR-Istituto di Struttura della Materia, U.O.S. di Monterotondo, Via Salaria Km. 29,300, 00015 Monterotondo St. (Roma), Italy
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10
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Lee J, Hogan CJ. Computational predictions of porosities, pore size distributions, and conductivities of aerosol deposited particulate films. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2020.09.078] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Ruiz-Garcia H, Alvarado-Estrada K, Krishnan S, Quinones-Hinojosa A, Trifiletti DM. Nanoparticles for Stem Cell Therapy Bioengineering in Glioma. Front Bioeng Biotechnol 2020; 8:558375. [PMID: 33365304 PMCID: PMC7750507 DOI: 10.3389/fbioe.2020.558375] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 10/19/2020] [Indexed: 12/16/2022] Open
Abstract
Gliomas are a dismal disease associated with poor survival and high morbidity. Current standard treatments have reached a therapeutic plateau even after combining maximal safe resection, radiation, and chemotherapy. In this setting, stem cells (SCs) have risen as a promising therapeutic armamentarium, given their intrinsic tumor homing as well as their natural or bioengineered antitumor properties. The interplay between stem cells and other therapeutic approaches such as nanoparticles holds the potential to synergize the advantages from the combined therapeutic strategies. Nanoparticles represent a broad spectrum of synthetic and natural biomaterials that have been proven effective in expanding diagnostic and therapeutic efforts, either used alone or in combination with immune, genetic, or cellular therapies. Stem cells have been bioengineered using these biomaterials to enhance their natural properties as well as to act as their vehicle when anticancer nanoparticles need to be delivered into the tumor microenvironment in a very precise manner. Here, we describe the recent developments of this new paradigm in the treatment of malignant gliomas.
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Affiliation(s)
- Henry Ruiz-Garcia
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, United States.,Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, United States
| | | | - Sunil Krishnan
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, United States
| | | | - Daniel M Trifiletti
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, United States.,Department of Neurological Surgery, Mayo Clinic, Jacksonville, FL, United States
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12
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Chen X, Seto T, Kortshagen UR, Hogan CJ. Size and structural characterization of Si nanocrystal aggregates from a low pressure nonthermal plasma reactor. POWDER TECHNOL 2020. [DOI: 10.1016/j.powtec.2020.06.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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13
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Ramiro I, Kundu B, Dalmases M, Özdemir O, Pedrosa M, Konstantatos G. Size- and Temperature-Dependent Intraband Optical Properties of Heavily n-Doped PbS Colloidal Quantum Dot Solid-State Films. ACS NANO 2020; 14:7161-7169. [PMID: 32396326 DOI: 10.1021/acsnano.0c02033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Steady-state access to intraband transitions in colloidal quantum dots (CQDs), via doping, permits exploitation of the electromagnetic spectrum at energies below the band gap. CQD intraband optoelectronics allows envisaging cheap mid- and long-wavelength infrared photodetectors and light-emitting devices, which today employ epitaxial materials. As intraband devices start to emerge, thorough studies of the basic properties of intraband transitions in different CQD materials are needed to guide technological research. In this work, we investigate the size and temperature dependence of the intraband transition in heavily n-doped PbS quantum dot (QD) films. In the studied QD size range (5-8 nm), the intraband energy spans from 209 to 151 meV. We measure the intraband absorption coefficient of heavily doped PbS QD films to be around 2 × 104 cm-1, proving that intraband absorption is as strong as interband absorption. We demonstrate a negative dependence of the intraband energy with temperature, in contrast to the positive dependence of the interband transition. Also opposite to the interband case, the temperature dependence of the intraband energy increases with decreasing size, going from -29 μeV/K to -49 μeV/K in the studied size range.
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Affiliation(s)
- Iñigo Ramiro
- Institut de Ciències Fotòniques (ICFO), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
| | - Biswajit Kundu
- Institut de Ciències Fotòniques (ICFO), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
| | - Mariona Dalmases
- Institut de Ciències Fotòniques (ICFO), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
| | - Onur Özdemir
- Institut de Ciències Fotòniques (ICFO), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
| | - María Pedrosa
- Institut de Ciències Fotòniques (ICFO), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
| | - Gerasimos Konstantatos
- Institut de Ciències Fotòniques (ICFO), The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010 Barcelona, Spain
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14
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Chen Q, Thimsen E. Highly Conductive Sb-SnO 2 Nanocrystals Synthesized by Dual Nonthermal Plasmas. ACS APPLIED MATERIALS & INTERFACES 2020; 12:25168-25177. [PMID: 32393020 DOI: 10.1021/acsami.0c05039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nonthermal plasma synthesis of transparent conducting oxide nanocrystals can offer advantages, for example, ligand-free surfaces, over traditionally used colloidal synthesis methods. When it comes to multicomponent (doped) metal oxide nanocrystal synthesis, uniform distribution of different metal elements and suppressing surface segregation of secondary resistive phases have been concerns. Specifically, surface segregation of resistive secondary phases reduces the electrical conductivity of nanocrystal assemblies. In this work, we demonstrate a nonthermal dual-plasma synthesis method capable of forming Sb-SnO2 (ATO) nanocrystals with a uniform composition distribution and apparently insignificant surface segregation of the dopant. A drastic increase in conductivity was observed in ATO thin films comprised of nanocrystals formed using a dual-plasma configuration compared to nanocrystals formed using a single-plasma configuration. The conductivity values of as-deposited porous films comprised of ATO nanocrystals, prepared using the dual-plasma approach, were on the order of 0.1 S cm-1, which to our knowledge is the highest conductivity reported to-date for that type of high surface area material. Annealing the films comprised of ATO nanocrystals at 500 °C for 2 h in air increased the conductivity and improved ambient stability, without significantly affecting the crystallite size.
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Affiliation(s)
- Qinyi Chen
- Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
| | - Elijah Thimsen
- Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
- Department of Energy, Environmental and Chemical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, United States
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15
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Bo R, Zhang F, Bu S, Nasiri N, Di Bernardo I, Tran-Phu T, Shrestha A, Chen H, Taheri M, Qi S, Zhang Y, Mulmudi HK, Lipton-Duffin J, Gaspera ED, Tricoli A. One-Step Synthesis of Porous Transparent Conductive Oxides by Hierarchical Self-Assembly of Aluminum-Doped ZnO Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2020; 12:9589-9599. [PMID: 32019296 DOI: 10.1021/acsami.9b19423] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Transparent conductive oxides (TCOs) are highly desirable for numerous applications ranging from photovoltaics to light-emitting diodes and photoelectrochemical devices. Despite progress, it remains challenging to fabricate porous TCOs (pTCOs) that may provide, for instance, a hierarchical nanostructured morphology for the separation of photoexcited hole/electron couples. Here, we present a facile process for the fabrication of porous architectures of aluminum-doped zinc oxide (AZO), a low-cost and earth-abundant transparent conductive oxide. Three-dimensional nanostructured films of AZO with tunable porosities from 10 to 98% were rapidly self-assembled from flame-made nanoparticle aerosols. Successful Al doping was confirmed by X-ray photoemission spectroscopy, high-resolution transmission electron microscopy, elemental mapping, X-ray diffraction, and Fourier transform infrared spectroscopy. An optimal Al-doping level of 1% was found to induce the highest material conductivity, while a higher amount led to partial segregation and formation of aluminum oxide domains. A controllable semiconducting to conducting behavior with a resistivity change of more than 4 orders of magnitudes from about 3 × 102 to 9.4 × 106 Ω cm was observed by increasing the AZO film porosity from 10 to 98%. While the denser AZO morphologies may find immediate application as transparent electrodes, we demonstrate that the ultraporous semiconducting layers have potential as a light-driven gas sensor, showing a high response of 1.92-1 ppm of ethanol at room temperature. We believe that these tunable porous transparent conductive oxides and their scalable fabrication method may provide a highly performing material for future optoelectronic devices.
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Affiliation(s)
- Renheng Bo
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Fan Zhang
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
- Department of Applied Chemistry , Northwestern Polytechnical University , Xi'an 710072 , China
- College of Energy Engineering , Nanjing Tech University , Nanjing 211816 , China
| | - Shulin Bu
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Noushin Nasiri
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
- School of engineering , Macquarie University , Sydney , New South Wales 2109 , Australia
| | - Iolanda Di Bernardo
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Thanh Tran-Phu
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Aabhash Shrestha
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Hongjun Chen
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Mahdiar Taheri
- Labotatory of Advanced Nanomaterials for Sustainability, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Shuhua Qi
- Department of Applied Chemistry , Northwestern Polytechnical University , Xi'an 710072 , China
| | - Yi Zhang
- College of Energy Engineering , Nanjing Tech University , Nanjing 211816 , China
| | - Hemant Kumar Mulmudi
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
| | - Josh Lipton-Duffin
- Institute for Future Environments (IFE) and Central Analytical Research Facility (CARF) , Queensland University of Technology (QUT) , Level 6, P Block, Gardens Point campus, 2 George St. Brisbane , Queensland 4000 , Australia
| | | | - Antonio Tricoli
- Nanotechnology Research Laboratory, Research School of Engineering , Australian National University , Canberra 2601 , Australia
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16
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Ghosh S, Chen X, Li C, Olson BA, Hogan CJ. Fragmentation and film growth in supersonic nanoaggregate aerosol deposition. AIChE J 2019. [DOI: 10.1002/aic.16874] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Souvik Ghosh
- Department of Mechanical Engineering University of Minnesota Minneapolis Minnesota
| | - Xiaoshuang Chen
- Department of Mechanical Engineering University of Minnesota Minneapolis Minnesota
| | - Chenxi Li
- Department of Mechanical Engineering University of Minnesota Minneapolis Minnesota
| | - Bernard A. Olson
- Department of Mechanical Engineering University of Minnesota Minneapolis Minnesota
| | - Christopher J. Hogan
- Department of Mechanical Engineering University of Minnesota Minneapolis Minnesota
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17
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Gibbs SL, Staller CM, Milliron DJ. Surface Depletion Layers in Plasmonic Metal Oxide Nanocrystals. Acc Chem Res 2019; 52:2516-2524. [PMID: 31424914 DOI: 10.1021/acs.accounts.9b00287] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Strong infrared (IR) light-matter interaction and spectral tunability combine to make plasmonic metal oxide nanocrystals (NCs) a compelling choice for IR applications. In particular, visible transparency paired with strong, dynamically tunable IR absorption has motivated their implementation in electrochromic smart windows, but these NCs hold promise for a far broader range of plasmonically driven processes such as surface-enhanced infrared sensing, photothermal therapy, and enhanced photocatalysis. These unique properties result from localized surface plasmon resonance (LSPR) sustained by a relatively low free charge carrier concentration, which in turn requires consideration of distinct materials physics relative to traditional plasmonic materials (i.e., metals). Particularly important is the formation of insulating shells devoid of charge carriers (depletion layers) near the NC surface. Surface states as well as applied surface potentials can give rise to a potential difference between the NC surface and its core that depletes free charge carriers from the surface, forming an insulating shell that reduces the conductivity in NC films, lowers the dielectric sensitivity of the LSPR, and diminishes the incident electric field enhancement. In this Account, we report recent investigations of depletion layers in plasmonic metal oxide NCs that have advanced understanding of the semiconductor physics underlying the optoelectronic properties of these NCs and the electrochemical modulation of their LSPR, establishing a conceptual framework with which to broaden their applicability and optimize their performance. As a result of surface depletion, larger, highly doped NCs have improved dielectric sensitivity compared with their smaller, lightly doped counterparts. Concentrating dopants near the NC surface compresses the depletion layer, resulting in improved conductivity of NC films. Moreover, atomic layer deposition of alumina to infill NC films enhances the film conductivity by more than 2 orders of magnitude, ascribed to the elimination of depletion effects by reactive removal of surface water species. At the conclusion, we reflect on how our newfound understanding of surface depletion in plasmonic metal oxide NCs is quickly leading to rational material design. This insight is already resulting in significant performance improvements, and the same principles can be applied to new, exciting opportunities in hot carrier extraction and resonant IR energy transduction.
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Affiliation(s)
- Stephen L. Gibbs
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712-1589, United States
| | - Corey M. Staller
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712-1589, United States
| | - Delia J. Milliron
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712-1589, United States
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18
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Greenberg BL, Robinson ZL, Ayino Y, Held JT, Peterson TA, Mkhoyan KA, Pribiag VS, Aydil ES, Kortshagen UR. Metal-insulator transition in a semiconductor nanocrystal network. SCIENCE ADVANCES 2019; 5:eaaw1462. [PMID: 31467972 PMCID: PMC6707780 DOI: 10.1126/sciadv.aaw1462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 07/15/2019] [Indexed: 06/01/2023]
Abstract
Many envisioned applications of semiconductor nanocrystals (NCs), such as thermoelectric generators and transparent conductors, require metallic (nonactivated) charge transport across an NC network. Although encouraging signs of metallic or near-metallic transport have been reported, a thorough demonstration of nonzero conductivity, σ, in the 0 K limit has been elusive. Here, we examine the temperature dependence of σ of ZnO NC networks. Attaining both higher σ and lower temperature than in previous studies of ZnO NCs (T as low as 50 mK), we observe a clear transition from the variable-range hopping regime to the metallic regime. The critical point of the transition is distinctly marked by an unusual power law close to σ ∝ T 1/5. We analyze the critical conductivity data within a quantum critical scaling framework and estimate the metal-insulator transition (MIT) criterion in terms of the free electron density, n, and interparticle contact radius, ρ.
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Affiliation(s)
| | - Zachary L. Robinson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Yilikal Ayino
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Jacob T. Held
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Timothy A. Peterson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - K. Andre Mkhoyan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Vlad S. Pribiag
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Eray S. Aydil
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN, USA
| | - Uwe R. Kortshagen
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, USA
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19
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Abstract
It is widely reported during last decade on the observation of room temperature ferromagnetism (RTFM) in doped ZnO and other transition metal oxides. However, the origin of RTFM is not understood and highly debated. While investigating the origin of RTFM, magnetic ion doped oxides should be excluded because it is not yet settled whether RTFM is intrinsic or due to the magnetic ion cluster in ZnO. Hence, it is desirable to investigate the origin of RTFM in non-magnetic ion doped ZnO and Cu-doped ZnO will be most suitable for this purpose. The important features of ferromagnetism observed in doped ZnO are (i) observation of RTFM at a doping concentration much below than the percolation threshold of wurtzite ZnO, (ii) temperature independence of magnetization and (iii) almost anhysteretic magnetization curve. We show that all these features of ferromagnetism in ZnO are due to overlapping of bound magnetic polarons (BMPs) which are created by exchange interaction between the spin of Cu2+ ion and spin of the localized hole due to zinc vacancy [Formula: see text]. Both the experimental and theoretical investigation show that the exchange interaction between Cu2+-Cu2+ ions mediated by [Formula: see text] is responsible for RTFM in Cu-doped ZnO.
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20
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Nava G, Fumagalli F, Neutzner S, Di Fonzo F. Large area porous 1D photonic crystals comprising silicon hierarchical nanostructures grown by plasma-assisted, nanoparticle jet deposition. NANOTECHNOLOGY 2018; 29:465603. [PMID: 30168445 DOI: 10.1088/1361-6528/aade21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this contribution, we describe a room-temperature, template-free, single-step approach for the growth of functional crystalline silicon nanostructures with tailored porosity and photonic properties. The method employs a plasma-assisted nanoparticle synthesis reactor in combination with a supersonic jet deposition stage, in what we call nanoparticle jet deposition or plasma-assisted, supersonic aerosol jet deposition. The relationship between plasma parameters, nanoparticle impaction conditions and the resulting silicon material structural characteristics is investigated. This understanding is successfully employed for the production of porous 1D photonic crystals obtained by periodically modulating the density of the hierarchical silicon nanostructures and hence their local refractive index. The open porosity of this device is then exploited in a proof of concept optical chemical sensor.
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Affiliation(s)
- Giorgio Nava
- Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, via Giovanni Pascoli 70/3, Milan, Italy. Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci, 32, I-20133 Milano, Italy
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21
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Benton BT, Greenberg BL, Aydil E, Kortshagen UR, Campbell SA. Variable range hopping conduction in ZnO nanocrystal thin films. NANOTECHNOLOGY 2018; 29:415202. [PMID: 30059013 DOI: 10.1088/1361-6528/aad6ce] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Zinc oxide (ZnO) nanocrystal films are of interest for new applications in thin film transistors and as transparent conductive oxides. Previous work has concentrated on achieving highly conductive, metallic films. This work focusses on the less explored insulating to semi-insulating regime, which enables obtaining deeper insights into the roles of surface states and defect states trapped at the nanocrystal interfaces. We examine the effects of various post-deposition treatments including controlled dosing with ultraviolet light, filling the voids between nanocrystals with a matrix material deposited by atomic layer deposition, and thermal annealing of the nanocrystal films. Both Mott and Efros-Shklovskii variable range hopping are observed depending on the carrier concentration in the nanocrystals. Using the above post-treatments to transition the films between the two conduction mechanisms enables determining the Fermi level density of states and the electron localization length. To interpret our results, we propose a model based on the assumption of nanocrystals consisting of quasi-neutral cores surrounded by shells depleted by surface OH trap states. The model suggests that the primary source of the increased conductivity in ZnO nanocrystal films based on post-treatments is an increase in the ability to tunnel between nanocrystals due to a reduction of the distance between the quasi-neutral nanocrystal cores.
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Affiliation(s)
- Brian T Benton
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, United States of America
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22
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Yu X, Yan H, Peng Q. Improve the Stability of Hybrid Halide Perovskite via Atomic Layer Deposition on Activated Phenyl-C 61 Butyric Acid Methyl Ester. ACS APPLIED MATERIALS & INTERFACES 2018; 10:28948-28954. [PMID: 30058323 DOI: 10.1021/acsami.8b06858] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Atomic layer deposition (ALD) of oxide film on [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) shows a great promise to dramatically improve the ambient stability of hybrid halide perovskite. The nucleation of an ALD oxide on PCBM is critical to reliably apply this strategy. In this paper, we present the first study of the nucleation behavior of ALD oxides, including Al2O3 and ZnO, on PCBM. We find that PCBM film acts a gas diffusion barrier blocking the ALD reactants (diethyl zinc) from etching the underlying CH3NH3PbI3. However, ZnO is not able to nucleate on PCBM. We further identify that trimethyl aluminum, a strongly Lewis acid, reacts readily with C═O on PCBM to generate a seeding layer for nucleating ZnO ALD. This new chemical route is highly reliable and can be used to synthesize ALD ZnO coatings over PCBM. The synthesized PCBM/Al2O3-ZnO dramatically improves the stability of CH3NH3PbI3 against the ambience and even against liquid water. The result signifies the importance of understanding of nucleation of ALD in enabling reliable barrier coatings for hybrid halide perovskites.
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Affiliation(s)
- Xiaozhou Yu
- Chemical and Biological Engineering Department , University of Alabama , P.O. Box 870203, Tuscaloosa 35487 , United States
| | - Haoming Yan
- Chemical and Biological Engineering Department , University of Alabama , P.O. Box 870203, Tuscaloosa 35487 , United States
| | - Qing Peng
- Chemical and Biological Engineering Department , University of Alabama , P.O. Box 870203, Tuscaloosa 35487 , United States
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23
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Palei M, Caligiuri V, Kudera S, Krahne R. Robust and Bright Photoluminescence from Colloidal Nanocrystal/Al 2O 3 Composite Films Fabricated by Atomic Layer Deposition. ACS APPLIED MATERIALS & INTERFACES 2018; 10:22356-22362. [PMID: 29893110 DOI: 10.1021/acsami.8b03769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Colloidal nanocrystals are a promising fluorescent class of materials whose spontaneous emission features can be tuned over a broad spectral range via their composition, geometry, and size. However, toward embedding nanocrystal films in elaborated device geometries, one significant drawback is the sensitivity of their emission properties on further fabrication processes like lithography, metal or oxide deposition, etc. In this work, we demonstrate how bright-emitting and robust thin films can be obtained by combining nanocrystal deposition from solutions via spin coating with subsequent atomic layer deposition of alumina. For the resulting composite films, the layer thickness can be controlled on the nanoscale and their refractive index can be finely tuned by the amount of deposited alumina. Ellipsometry is used to measure the real and imaginary part of the dielectric permittivity, which gives direct access to the wavelength dependent refractive index and absorbance of the film. Detailed analysis of the photophysics of thin films of core-shell nanocrystals with different shapes and different shell thicknesses allows to correlate the behavior of the photoluminescence and of the decay lifetime to the changes in the nonradiative rate that are induced by the alumina deposition. We show that the photoemission properties of such composite films are stable in wavelength and intensity over several months and that the photoluminescence completely recovers from heating processes up to 240 °C. The latter is particularly interesting since it demonstrates robustness to the typical heat treatment that is needed in several process steps like resist-based lithography and deposition by thermal or electron beam evaporation of metals or oxides.
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Affiliation(s)
- Milan Palei
- Nanochemistry Department , Istituto Italiano di Tecnologia , 16163 Genova , Italy
- Dipartimento di Chimica e Chimica Industriale , Universita di Genova , 16146 Genova , Italy
| | - Vincenzo Caligiuri
- Nanochemistry Department , Istituto Italiano di Tecnologia , 16163 Genova , Italy
| | - Stefan Kudera
- Nanochemistry Department , Istituto Italiano di Tecnologia , 16163 Genova , Italy
| | - Roman Krahne
- Nanochemistry Department , Istituto Italiano di Tecnologia , 16163 Genova , Italy
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24
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Staller CM, Robinson ZL, Agrawal A, Gibbs SL, Greenberg BL, Lounis SD, Kortshagen UR, Milliron DJ. Tuning Nanocrystal Surface Depletion by Controlling Dopant Distribution as a Route Toward Enhanced Film Conductivity. NANO LETTERS 2018; 18:2870-2878. [PMID: 29708349 DOI: 10.1021/acs.nanolett.7b05484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Electron conduction through bare metal oxide nanocrystal (NC) films is hindered by surface depletion regions resulting from the presence of surface states. We control the radial dopant distribution in tin-doped indium oxide (ITO) NCs as a means to manipulate the NC depletion width. We find in films of ITO NCs of equal overall dopant concentration that those with dopant-enriched surfaces show decreased depletion width and increased conductivity. Variable temperature conductivity data show electron localization length increases and associated depletion width decreases monotonically with increased density of dopants near the NC surface. We calculate band profiles for NCs of differing radial dopant distributions and in agreement with variable temperature conductivity fits find NCs with dopant-enriched surfaces have narrower depletion widths and longer localization lengths than those with dopant-enriched cores. Following amelioration of NC surface depletion by atomic layer deposition of alumina, all films of equal overall dopant concentration have similar conductivity. Variable temperature conductivity measurements on alumina-capped films indicate all films behave as granular metals. Herein, we conclude that dopant-enriched surfaces decrease the near-surface depletion region, which directly increases the electron localization length and conductivity of NC films.
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Affiliation(s)
- Corey M Staller
- McKetta Department of Chemical Engineering , University of Texas at Austin , Austin , Texas 78712-1589 , United States
| | - Zachary L Robinson
- Department of Physics , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Ankit Agrawal
- McKetta Department of Chemical Engineering , University of Texas at Austin , Austin , Texas 78712-1589 , United States
| | - Stephen L Gibbs
- McKetta Department of Chemical Engineering , University of Texas at Austin , Austin , Texas 78712-1589 , United States
| | - Benjamin L Greenberg
- Department of Mechanical Engineering , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Sebastien D Lounis
- The Molecular Foundry , Lawrence Berkeley National Laboratory , 1 Cyclotron Road , Berkeley , California 94720 , United States
- Graduate Group in Applied Science and Technology , University of California , Berkeley, Berkeley , California 94720 , United States
| | - Uwe R Kortshagen
- Department of Mechanical Engineering , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Delia J Milliron
- McKetta Department of Chemical Engineering , University of Texas at Austin , Austin , Texas 78712-1589 , United States
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25
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Kim BH, Staller CM, Cho SH, Heo S, Garrison CE, Kim J, Milliron DJ. High Mobility in Nanocrystal-Based Transparent Conducting Oxide Thin Films. ACS NANO 2018; 12:3200-3208. [PMID: 29553705 DOI: 10.1021/acsnano.7b06783] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Charge carrier mobility in transparent conducting oxide (TCO) films is mainly limited by impurity scattering, grain boundary scattering, and a hopping transport mechanism. We enhanced the mobility in nanocrystal (NC)-based TCO films, exceeding even typical values found in sputtered thin films, by addressing each of these scattering factors. Impurity scattering is diminished by incorporating cerium as a dopant in indium oxide NCs instead of the more typical dopant, tin. Grain boundary scattering is reduced by using large NCs with a size of 21 nm, which nonetheless were sufficiently small to avoid haze due to light scattering. In-filling of the precursor solution followed by annealing results in a NC-based composite film which conducts electrons through metal-like transport at room temperature, readily distinguished by the positive temperature coefficient of resistance. Cerium-doped indium oxide (Ce:In2O3) NC-based composite films achieve a high mobility of 56.0 cm2/V·s, and a low resistivity of 1.25 × 10-3 Ω·cm. The films are transparent to a broad range of visible and near-infrared light from 400 nm to at least 2500 nm wavelength. On the basis of the high conductivity and high transparency of the Ce:In2O3 NC-based composite films, the films are successfully applied as transparent electrodes within an electrochromic device.
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Affiliation(s)
- Byung Hyo Kim
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Corey M Staller
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Shin Hum Cho
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Sungyeon Heo
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Carrie E Garrison
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Jongwook Kim
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Delia J Milliron
- McKetta Department of Chemical Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
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26
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Galář P, Khun J, Kopecký D, Scholtz V, Trchová M, Fučíková A, Jirešová J, Fišer L. Influence of non-thermal plasma on structural and electrical properties of globular and nanostructured conductive polymer polypyrrole in water suspension. Sci Rep 2017; 7:15068. [PMID: 29118369 PMCID: PMC5678096 DOI: 10.1038/s41598-017-15184-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 10/23/2017] [Indexed: 11/09/2022] Open
Abstract
Non-thermal plasma has proved its benefits in medicine, plasma assisted polymerization, food industry and many other fields. Even though, the ability of non-thermal plasma to modify surface properties of various materials is generally known, only limited attention has been given to exploitations of this treatment on conductive polymers. Here, we show study of non-thermal plasma treatment on properties of globular and nanostructured polypyrrole in the distilled water. We observe that plasma presence over the suspension level doesn't change morphology of the polymer (shape), but significantly influences its elemental composition and physical properties. After 60 min of treatment, the relative concentration of chloride counter ions decreased approximately 3 and 4 times for nanostructured and globular form, respectively and concentration of oxygen increased approximately 3 times for both forms. Simultaneously, conductivity decrease (14 times for globular and 2 times for nanostructured one) and changes in zeta potential characteristics of both samples were observed. The modification evolution was dominated by multi-exponential function with time constants having values approximately 1 and 10 min for both samples. It is expected that these time constants are related to two modification processes connected to direct presence of the spark and to long-lived species generated by the plasma.
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Affiliation(s)
- Pavel Galář
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, 166 28, Czech Republic.
| | - Josef Khun
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, 166 28, Czech Republic
| | - Dušan Kopecký
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, 166 28, Czech Republic
| | - Vladimír Scholtz
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, 166 28, Czech Republic
| | - Miroslava Trchová
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague, 162 06, Czech Republic
| | - Anna Fučíková
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University in Prague, 121 16, Prague, Czech Republic
| | - Jana Jirešová
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, 166 28, Czech Republic
| | - Ladislav Fišer
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, 166 28, Czech Republic
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27
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Greenberg BL, Robinson ZL, Reich KV, Gorynski C, Voigt BN, Francis LF, Shklovskii BI, Aydil ES, Kortshagen UR. ZnO Nanocrystal Networks Near the Insulator-Metal Transition: Tuning Contact Radius and Electron Density with Intense Pulsed Light. NANO LETTERS 2017; 17:4634-4642. [PMID: 28704060 DOI: 10.1021/acs.nanolett.7b01078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Networks of ligand-free semiconductor nanocrystals (NCs) offer a valuable combination of high carrier mobility and optoelectronic properties tunable via quantum confinement. In principle, maximizing carrier mobility entails crossing the insulator-metal transition (IMT), where carriers become delocalized. A recent theoretical study predicted that this transition occurs at nρ3 ≈ 0.3, where n is the carrier density and ρ is the interparticle contact radius. In this work, we satisfy this criterion in networks of plasma-synthesized ZnO NCs by using intense pulsed light (IPL) annealing to tune n and ρ independently. IPL applied to as-deposited NCs increases ρ by inducing sintering, and IPL applied after the NCs are coated with Al2O3 by atomic layer deposition increases n by removing electron-trapping surface hydroxyls. This procedure does not substantially alter NC size or composition and is potentially applicable to a wide variety of nanomaterials. As we increase nρ3 to at least twice the predicted critical value, we observe conductivity scaling consistent with arrival at the critical region of a continuous quantum phase transition. This allows us to determine the critical behavior of the dielectric constant and electron localization length at the IMT. However, our samples remain on the insulating side of the critical region, which suggests that the critical value of nρ3 may in fact be significantly higher than 0.3.
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Affiliation(s)
| | | | - K V Reich
- Ioffe Institute , St Petersburg, 194021, Russia
| | - Claudia Gorynski
- Department of Mechanical and Process Engineering, University of Duisburg-Essen , Forsthausweg 2, 47057 Duisburg, Germany
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28
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Lee SY, Kim J, Park A, Park J, Seo H. Creation of a Short-Range Ordered Two-Dimensional Electron Gas Channel in Al 2O 3/In 2O 3 Interfaces. ACS NANO 2017; 11:6040-6047. [PMID: 28521101 DOI: 10.1021/acsnano.7b01964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The tuning of electrical properties in oxides via surface and interfacial two-dimensional electron gas (2DEG) channels is of great interest, as they reveal the extraordinary transition from insulating or semiconducting characteristics to metallic conduction or superconductivity enabled by the ballistic transport of spatially confined electrons. However, realizing the practical aspects of this exotic phenomenon toward short-range ordered and air-stable 2DEG channels remains a great challenge. At the heterointerface formed after deposition of an Al2O3 layer on a nanocrystalline In2O3 layer, a dramatic improvement in carrier conduction equivalent to metallic conduction is obtained. A conductivity increase by a factor of 1013 times that in raw In2O3, a sheet resistance of 850 Ω/cm2, and a room temperature Hall mobility of 20.5 cm2 V-1 s-1 are obtained, which are impossible to achieve by tuning each layer individually. The physicochemical origin of metallic conduction is mainly ascribed to the 2D interfacially confined O-vacancies and semimetallic nanocrystalline InOx (x < 2) phases by the clustered self-doping effect caused by O-extraction from In2O3 to the Al2O3 phase during ALD. Unlike other submetallic oxides, this 2D channel is air-stable by complete Al2O3 passivation and thereby promises applicability for implementation in devices.
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Affiliation(s)
- Sang Yeon Lee
- Department of Energy Systems Research & Department of Materials Science and Engineering, Ajou University , Suwon 16499, Republic of Korea
| | - Jinseo Kim
- Department of Energy Systems Research & Department of Materials Science and Engineering, Ajou University , Suwon 16499, Republic of Korea
| | - Ayoung Park
- Department of Energy Systems Research & Department of Materials Science and Engineering, Ajou University , Suwon 16499, Republic of Korea
| | - Jucheol Park
- Gyeongbuk Science Technology Promotion Center, Gumi Electronics & Information Technology Research Institute , Gumi 39171, Republic of Korea
| | - Hyungtak Seo
- Department of Energy Systems Research & Department of Materials Science and Engineering, Ajou University , Suwon 16499, Republic of Korea
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29
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Yin B, Sadtler B, Berezin MY, Thimsen E. Quantum dots protected from oxidative attack using alumina shells synthesized by atomic layer deposition. Chem Commun (Camb) 2016; 52:11127-30. [PMID: 27550790 PMCID: PMC7389310 DOI: 10.1039/c6cc05090e] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Applications of luminescent quantum dots require the materials to be stable under a wide range of temperatures, photon fluxes and chemical environments. In this work, we demonstrate that Al2O3 shells synthesized by atomic layer deposition on films of CdTe quantum dots are effective to prevent chemical degradation for up to 17 hours under continuous illumination at 90 °C in ambient air. Control samples with no Al2O3 coating experienced extensive oxidation and severe quenching of the photoluminescence intensity under these conditions.
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Affiliation(s)
- B. Yin
- Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, MO 63130, USA
| | - B. Sadtler
- Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, MO 63130, USA
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, MO 63130, USA
| | - M. Y. Berezin
- Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, MO 63130, USA
- Mallinckrodt Institute of Radiology, Washington University in Saint Louis, Saint Louis, MO 63130, USA
| | - E. Thimsen
- Institute of Materials Science and Engineering, Washington University in Saint Louis, Saint Louis, MO 63130, USA
- Department of Energy, Environmental and Chemical Engineering, Washington University in Saint Louis, Saint Louis, MO 63130, USA
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30
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Kortshagen UR, Sankaran RM, Pereira RN, Girshick SL, Wu JJ, Aydil ES. Nonthermal Plasma Synthesis of Nanocrystals: Fundamental Principles, Materials, and Applications. Chem Rev 2016; 116:11061-127. [DOI: 10.1021/acs.chemrev.6b00039] [Citation(s) in RCA: 248] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Uwe R. Kortshagen
- Department
of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - R. Mohan Sankaran
- Department
of Chemical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Rui N. Pereira
- Department
of Physics and I3N, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
- Walter
Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany
| | - Steven L. Girshick
- Department
of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Jeslin J. Wu
- Department
of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Eray S. Aydil
- Department
of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
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31
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Lanigan D, Thimsen E. Contact Radius and the Insulator-Metal Transition in Films Comprised of Touching Semiconductor Nanocrystals. ACS NANO 2016; 10:6744-6752. [PMID: 27398597 DOI: 10.1021/acsnano.6b02190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nanocrystal assemblies are being explored for a number of optoelectronic applications such as transparent conductors, photovoltaic solar cells, and electrochromic windows. Majority carrier transport is important for these applications, yet it remains relatively poorly understood in films comprised of touching nanocrystals. Specifically, the underlying structural parameters expected to determine the transport mechanism have not been fully elucidated. In this report, we demonstrate experimentally that the contact radius, between touching heavily doped ZnO nanocrystals, controls the electron transport mechanism. Spherical nanocrystals are considered, which are connected by a circular area. The radius of this circular area is the contact radius. For nanocrystals that have local majority carrier concentration above the Mott transition, there is a critical contact radius. If the contact radius between nanocrystals is less than the critical value, then the transport mechanism is variable range hopping. If the contact radius is greater than the critical value, the films display behavior consistent with metallic electron transport.
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Affiliation(s)
- Deanna Lanigan
- Interface Research Group, Department of Energy, Environmental and Chemical Engineering, Washington University in Saint Louis , Saint Louis, Missouri 63130, United States
| | - Elijah Thimsen
- Interface Research Group, Department of Energy, Environmental and Chemical Engineering, Washington University in Saint Louis , Saint Louis, Missouri 63130, United States
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32
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Park DS, Wang H, Vasheghani Farahani SK, Walker M, Bhatnagar A, Seghier D, Choi CJ, Kang JH, McConville CF. Surface passivation of semiconducting oxides by self-assembled nanoparticles. Sci Rep 2016; 6:18449. [PMID: 26757827 PMCID: PMC4725940 DOI: 10.1038/srep18449] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/12/2015] [Indexed: 11/13/2022] Open
Abstract
Physiochemical interactions which occur at the surfaces of oxide materials can significantly impair their performance in many device applications. As a result, surface passivation of oxide materials has been attempted via several deposition methods and with a number of different inert materials. Here, we demonstrate a novel approach to passivate the surface of a versatile semiconducting oxide, zinc oxide (ZnO), evoking a self-assembly methodology. This is achieved via thermodynamic phase transformation, to passivate the surface of ZnO thin films with BeO nanoparticles. Our unique approach involves the use of BexZn1-xO (BZO) alloy as a starting material that ultimately yields the required coverage of secondary phase BeO nanoparticles, and prevents thermally-induced lattice dissociation and defect-mediated chemisorption, which are undesirable features observed at the surface of undoped ZnO. This approach to surface passivation will allow the use of semiconducting oxides in a variety of different electronic applications, while maintaining the inherent properties of the materials.
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Affiliation(s)
- Dae-Sung Park
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Haiyuan Wang
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | | | - Marc Walker
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Akash Bhatnagar
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Djelloul Seghier
- Science Institute, University of Iceland, Dunhaga 3, Reykjavik, IS-107, Iceland
| | - Chel-Jong Choi
- School of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonju, 561-756, Republic of Korea
| | - Jie-Hun Kang
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom.,Department of Nano and Electronic Physics, Kookmin University, Seoul, 136-702, Republic of Korea
| | - Chris F McConville
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
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33
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Greenberg BL, Ganguly S, Held JT, Kramer NJ, Mkhoyan KA, Aydil ES, Kortshagen UR. Nonequilibrium-Plasma-Synthesized ZnO Nanocrystals with Plasmon Resonance Tunable via Al Doping and Quantum Confinement. NANO LETTERS 2015; 15:8162-8169. [PMID: 26551232 DOI: 10.1021/acs.nanolett.5b03600] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Metal oxide semiconductor nanocrystals (NCs) exhibit localized surface plasmon resonances (LSPRs) tunable within the infrared (IR) region of the electromagnetic spectrum by vacancy or impurity doping. Although a variety of these NCs have been produced using colloidal synthesis methods, incorporation and activation of dopants in the liquid phase has often been challenging. Herein, using Al-doped ZnO (AZO) NCs as an example, we demonstrate the potential of nonthermal plasma synthesis as an alternative strategy for the production of doped metal oxide NCs. Exploiting unique, thoroughly nonequilibrium synthesis conditions, we obtain NCs in which dopants are not segregated to the NC surfaces and local doping levels are high near the NC centers. Thus, we achieve overall doping levels as high as 2 × 10(20) cm(-3) in NCs with diameters ranging from 12.6 to 3.6 nm, and for the first time experimentally demonstrate a clear quantum confinement blue shift of the LSPR energy in vacancy- and impurity-doped semiconductor NCs. We propose that doping of central cores and heavy doping of small NCs are achievable via nonthermal plasma synthesis, because chemical potential differences between dopant and host atoms-which hinder dopant incorporation in colloidal synthesis-are irrelevant when NC nucleation and growth proceed via irreversible interactions among highly reactive gas-phase ions and radicals and ligand-free NC surfaces. We explore how the distinctive nucleation and growth kinetics occurring in the plasma influences dopant distribution and activation, defect structure, and impurity phase formation.
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Affiliation(s)
- Benjamin L Greenberg
- Department of Mechanical Engineering and ‡Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Shreyashi Ganguly
- Department of Mechanical Engineering and ‡Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Jacob T Held
- Department of Mechanical Engineering and ‡Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Nicolaas J Kramer
- Department of Mechanical Engineering and ‡Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - K Andre Mkhoyan
- Department of Mechanical Engineering and ‡Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Eray S Aydil
- Department of Mechanical Engineering and ‡Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Uwe R Kortshagen
- Department of Mechanical Engineering and ‡Department of Chemical Engineering and Materials Science, University of Minnesota , Minneapolis, Minnesota 55455, United States
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34
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Meric Z, Mehringer C, Karpstein N, Jank MPM, Peukert W, Frey L. Tunable conduction type of solution-processed germanium nanoparticle based field effect transistors and their inverter integration. Phys Chem Chem Phys 2015; 17:22106-14. [DOI: 10.1039/c5cp03321g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Top and cross-sectional view of a Ge NP layer deposited from dispersion. Due to specific ALD post processing ambipolar TFTs can be fabricated from those layers. A circuit employing two ambipolar TFTs functions as a NOT gate with an inverter gain of up to 4.
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Affiliation(s)
- Zeynep Meric
- Chair of Electron Devices
- Friedrich-Alexander-Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Christian Mehringer
- Institute of Particle Technology
- Friedrich-Alexander-Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Nicolas Karpstein
- Chair of Electron Devices
- Friedrich-Alexander-Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Michael P. M. Jank
- Fraunhofer Institute for Integrated Systems and Device Technology
- 91058 Erlangen
- Germany
| | - Wolfgang Peukert
- Institute of Particle Technology
- Friedrich-Alexander-Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
| | - Lothar Frey
- Chair of Electron Devices
- Friedrich-Alexander-Universität Erlangen-Nürnberg
- 91058 Erlangen
- Germany
- Fraunhofer Institute for Integrated Systems and Device Technology
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