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Bai L, Li Y, Zhao J, Bao Y, Ji L, Dai J, Shi H, Yang F, Zhang X. Highly Efficient Utilization of Precious Metals for Hydrogen Evolution Reaction with Photo‐Assisted Electro‐Deposited Urchin‐Like Te Nanostructure as a Template. ChemCatChem 2019. [DOI: 10.1002/cctc.201900125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ling Bai
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Yujie Li
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Jun Zhao
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Yunkai Bao
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Lifei Ji
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Jianying Dai
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Huilan Shi
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Fengchun Yang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
| | - Xin Zhang
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education) College of Chemistry and Material Science National Demonstration Center for Experimental Chemistry EducationNorthwest University Xi'an 710069 P. R. China
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Lee SH, Lee SW, Oh T, Petrosko SH, Mirkin CA, Jang JW. Direct Observation of Plasmon-Induced Interfacial Charge Separation in Metal/Semiconductor Hybrid Nanostructures by Measuring Surface Potentials. NANO LETTERS 2018; 18:109-116. [PMID: 29140713 DOI: 10.1021/acs.nanolett.7b03540] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Plasmon-induced interfacial charge separation (PICS) is one of the key processes responsible for the improved conversion efficiencies of energy-harvesting devices that incorporate metal nanostructures. In this Letter, we reveal a mechanism of PICS by visualizing (with nanometer-scale resolution) and characterizing plasmon-exciton coupling between p-type poly(pyrrole) (PPy) nanowires (NWs) and Ag nanoparticles (NPs) using light-irradiated Kelvin probe force microscopy (KPFM). Under blue-light irradiation, the Ag NPs are expected to donate electrons to the PPy NWs via a hot electron injection process. However, in this Letter, we observe that under blue-light irradiation the plasmonically and excitonically excited electrons in the semiconductor back-transfer to the metal. The PICS in this system can be explained by comparing it with a similar one where Au NPs are attached to n-type ZnO NWs; we observed a net electron transfer from the Au NPs to the ZnO NWs (an upward band bending is formed at the interface of the two materials, presumably obstructing electron back-transfer). Indeed, energy band matching between the metal and the semiconductor components of hybrid nanostructures influences PICS pathways. These experimental findings and our proposed mechanism consistently explain the PICS occurring in the PPy NW-Ag NP system with important implications on explaining their cooperative optoelectronic activities.
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Affiliation(s)
- Seung-Hoon Lee
- Department of Physics, Pukyong National University , Busan 48513, Republic of Korea
| | - Seung Woo Lee
- School of Chemical Engineering, Yeungnam University , Gyeongsan, 38541, Republic of Korea
| | | | | | | | - Jae-Won Jang
- Department of Physics, Pukyong National University , Busan 48513, Republic of Korea
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Li DB, Sun XJ, Jia YP, Stockman MI, Paudel HP, Song H, Jiang H, Li ZM. Direct observation of localized surface plasmon field enhancement by Kelvin probe force microscopy. LIGHT, SCIENCE & APPLICATIONS 2017; 6:e17038. [PMID: 30167283 PMCID: PMC6062315 DOI: 10.1038/lsa.2017.38] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 05/21/2023]
Abstract
A surface plasmon (SP) is a fundamental excitation state that exists in metal nanostructures. Over the past several years, the performance of optoelectronic devices has been improved greatly via the SP enhancement effect. In our previous work, the responsivity of GaN ultraviolet detectors was increased by over 30 times when using Ag nanoparticles. However, the physics of the SP enhancement effect has not been established definitely because of the lack of experimental evidence. To reveal the physical origin of this enhancement, Kelvin probe force microscopy (KPFM) was used to observe the SP-induced surface potential reduction in the vicinity of Ag nanoparticles on a GaN epilayer. Under ultraviolet illumination, the localized field enhancement induced by the SP forces the photogenerated electrons to drift close to the Ag nanoparticles, leading to a reduction of the surface potential around the Ag nanoparticles on the GaN epilayer. For an isolated Ag nanoparticle with a diameter of ~200 nm, the distribution of the SP localized field is located within 60 nm of the boundary of the Ag nanoparticle. For a dimer of Ag nanoparticles, the localized field enhancement between the nanoparticles was the strongest. The results presented here provide direct experimental proof of the localized field enhancement. These results not only explain the high performance of GaN detectors observed with the use of Ag nanoparticles but also reveal the physical mechanism of SP enhancement in optoelectronic devices, which will help us further understand and improve the performance of SP-based optoelectronic devices in the future.
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Affiliation(s)
- Da-Bing Li
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Xiao-Juan Sun
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Yu-Ping Jia
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Mark I Stockman
- Center for Nano-Optics (CeNO) and Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30340, USA
| | - Hari P Paudel
- Center for Nano-Optics (CeNO) and Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30340, USA
| | - Hang Song
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Hong Jiang
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Zhi-Ming Li
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
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BERCU N, GIRAUDET L, SIMONETTI O, MOLINARI M. Development of an improved Kelvin probe force microscope for accurate local potential measurements on biased electronic devices. J Microsc 2017; 267:272-279. [DOI: 10.1111/jmi.12563] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/14/2017] [Indexed: 11/30/2022]
Affiliation(s)
- N.B. BERCU
- Laboratoire de Recherche en Nanosciences (LRN EA4682); Université de Reims Champagne-Ardenne; Reims France
| | - L. GIRAUDET
- Laboratoire de Recherche en Nanosciences (LRN EA4682); Université de Reims Champagne-Ardenne; Reims France
| | - O. SIMONETTI
- Laboratoire de Recherche en Nanosciences (LRN EA4682); Université de Reims Champagne-Ardenne; Reims France
| | - M. MOLINARI
- Laboratoire de Recherche en Nanosciences (LRN EA4682); Université de Reims Champagne-Ardenne; Reims France
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Lan F, Jiang M, Tao Q, Wei F, Li G. Reconstruction of Kelvin probe force microscopy image with experimentally calibrated point spread function. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:033704. [PMID: 28372383 DOI: 10.1063/1.4978282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A Kelvin probe force microscopy (KPFM) image is sometimes difficult to interpret because it is a blurred representation of the true surface potential (SP) distribution of the materials under test. The reason for the blurring is that KPFM relies on the detection of electrostatic force, which is a long-range force compared to other surface forces. Usually, KPFM imaging model is described as the convolution of the true SP distribution of the sample with an intrinsic point spread function (PSF) of the measurement system. To restore the true SP signals from the blurred ones, the intrinsic PSF of the system is needed. In this work, we present a way to experimentally calibrate the PSF of the KPFM system. Taking the actual probe shape and experimental parameters into consideration, this calibration method leads to a more accurate PSF than the ones obtained from simulations. Moreover, a nonlinear reconstruction algorithm based on total variation (TV) regularization is applied to KPFM measurement to reverse the blurring caused by PSF during KPFM imaging process; as a result, noises are reduced and the fidelity of SP signals is improved.
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Affiliation(s)
- Fei Lan
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - Minlin Jiang
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - Quan Tao
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - Fanan Wei
- School of Machine Engineering and Automation, Fuzhou University, Fujian 350116, China
| | - Guangyong Li
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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Kim MR, Hafez HA, Chai X, Besteiro LV, Tan L, Ozaki T, Govorov AO, Izquierdo R, Ma D. Covellite CuS nanocrystals: realizing rapid microwave-assisted synthesis in air and unravelling the disappearance of their plasmon resonance after coupling with carbon nanotubes. NANOSCALE 2016; 8:12946-12957. [PMID: 27304092 DOI: 10.1039/c6nr03426h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Semiconductor nanocrystals that show plasmonic resonance represent an emerging class of highly promising plasmonic materials with potential applications in diverse fields, such as sensing and optical and optoelectronic devices. We report a new approach to synthesizing homogeneous covellite CuS nanoplatelets in air and the almost complete disappearance of their plasmonic resonance once coupled with multiwalled carbon nanotubes (MWCNTs). These nanoplatelets were rapidly synthesized by a simple microwave-assisted approach at a relatively low reaction temperature in air, instead of under N2 as reported previously. These less severe synthesis conditions were enabled by appropriately selecting a Cu precursor and preparing a precursor sulfur solution (instead of using solid sulfur) and by using microwave radiation as the heat source. The advantages of utilizing microwave irradiation, including uniform and rapid heating, became clear after comparing the results of the synthesis with those achieved using a conventional oil-bath method under N2. The CuS nanoplatelets prepared in this way showed very strong plasmon resonance at c. 1160 nm as a result of their free charge carriers at the calculated density of nh = 1.5 × 10(22) cm(-3) based on the Drude model. With the aim of exploring their potential for near-infrared responsive optoelectronic devices, they were hybridized with functionalized MWCNTs. Their strong plasmon resonance almost completely disappeared on hybridization. Detailed investigations excluded the effect of possible structural changes in the CuS nanoplatelets during the hybridization process and a possible effect on the plasmon resonance arising from the chemical bonding of surface ligands. Charge transfer was considered to be the main reason for the almost complete disappearance of the plasmon resonance, which was further confirmed by terahertz (THz) time-domain spectrometry and THz time-resolved spectrometry measurements performed on the CuS-MWCNT nanohybrids. By extracting the rising and relaxation constants through fitting a single-exponential rising function and a bi-exponential relaxation function, in combination with the results of THz differential transmission as a function of the NIR pump fluence, it was found that hole injection changed the electronic properties of the MWCNTs only subtly on a short picosecond time scale, whereas the nature of the band structure of the MWCNTs remained largely unchanged. These findings aid our understanding of recently emerging semiconductor plasmonics and will also help in developing practical applications.
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Affiliation(s)
- Mee Rahn Kim
- Centre-Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, 1650 Boulevard Lionel-Boulet, Varennes, Québec J3X 1S2, Canada.
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Bunes BR, Xu M, Zhang Y, Gross DE, Saha A, Jacobs DL, Yang X, Moore JS, Zang L. Photodoping and enhanced visible light absorption in single-walled carbon nanotubes functionalized with a wide band gap oligomer. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:162-167. [PMID: 25367178 DOI: 10.1002/adma.201404112] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 10/09/2014] [Indexed: 06/04/2023]
Abstract
Carbon nanotubes feature excellent electronic properties but narrow absorption bands limit their utility in certain optoelectronic devices, including photovoltaic cells. Here, the addition of a wide-bandgap gap oligomer enhances light absorption in the visible spectrum. Furthermore, the oligomer interacts with the carbon nanotube through a peculiar charge transfer, which provides insight into Type II heterojunctions.
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Affiliation(s)
- Benjamin R Bunes
- Nano Institute of Utah and Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah, 84112, USA
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Long R, Prezhdo OV. Asymmetry in the electron and hole transfer at a polymer-carbon nanotube heterojunction. NANO LETTERS 2014; 14:3335-3341. [PMID: 24841921 DOI: 10.1021/nl500792a] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
To achieve a high photon-to-charge conversion efficiency, the electron-hole pair generated by photon absorption in organic photovoltaic systems must overcome the Coulomb attraction, which often results in voltage loss. Bearing this in mind, we performed ab initio time-domain simulations of the charge separation and energy relaxation across an interface formed by poly(3-hexylthiophene) (P3HT) and a single-walled carbon nanotube (CNT). The dynamics of the positive and negative charges showed strong asymmetry. Photoexcitation of the polymer leads to a 100 fs electron transfer, in agreement with the experiment, followed by a loss of 0.6 eV of energy within 0.5 ps. Photoexcitation of the CNT leads to hole transfer, which requires nearly 2 ps, but loses only 0.3 eV of energy. The strong disparity arises due to the differences in the localization of the photoexcited donor states, the number densities of the acceptor states, and the phonon modes involved. Used as a chromophore, P3HT produces faster charge separation but leads to larger energy losses and cannot harvest light in the red region of the solar spectrum. In contrast, CNT absorbs a broader range of photons and reduces energy losses but gives a less efficient charge separation. The complementary properties of the two chromophores can be utilized to improve the performance of solar cells by optimizing simultaneously light harvesting, charge separation, and energy relaxation, which affect the photovoltaic yield, current, and voltage.
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Affiliation(s)
- Run Long
- School of Physics, Complex & Adaptive Systems Laboratory, University College Dublin , Belfield, Dublin 4, Ireland
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In situ chemical oxidative graft polymerization of thiophene derivatives from multi-walled carbon nanotubes. JOURNAL OF POLYMER RESEARCH 2014. [DOI: 10.1007/s10965-014-0442-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Long R, Guo M, Ziletti A. Charge separation across P3HT/carbon nanotube interface: First-principles calculations of electronic structures. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.02.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Vizuete M, Gómez-Escalonilla MJ, Fierro JLG, Ohkubo K, Fukuzumi S, Yudasaka M, Iijima S, Nierengarten JF, Langa F. Photoinduced electron transfer in a carbon nanohorn–C60 conjugate. Chem Sci 2014. [DOI: 10.1039/c3sc53342e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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