1
|
Wei X, Zhang Q, Cui Z, Yang D, Mei S, Zhang W, Xie H, Yu K, Guo R, Wei W. Mapping the Identity of Transition Metal Doping and Surface Passivation in Indium Phosphide with Theoretical Calculation. Inorg Chem 2023; 62:15258-15266. [PMID: 37671490 DOI: 10.1021/acs.inorgchem.3c02455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
Understanding the electronic structure of doped InP quantum dots (QDs) is essential to optimize the material for specific optoelectronic applications. However, current synthesis approaches are often tedious and unfavorable for rational tunning. Herein, a combination of experimental and computational studies was conducted to address the doping mechanism and surface passivation of InP QDs. The successful dopant introduction requires low Cu doping concentration and heavy Mn doping, while the Ag doping amount is relatively moderate. This may correspond to the theoretical doping formation energy presented as Cu (-2.52 eV) < Ag (-1.76 eV) < Mn (-0.38 eV). As for surface passivation, inorganic ions and shell-like ZnS are unraveled through simulational investigation. Chloride ion promotes oriented growth toward tetrahedron morphology while nitrate-passivated InP QDs exhibit blurry transmission electron microscope (TEM) morphology. Correspondingly, the binding energy of chloride ion with (111) facet is -2.13 eV significantly lower than those of (110) and (100) facets. Further, the additional Zn 3d bands are more involved in the formation of conduction band, which optimized the Mn-doped InP with a 0.32 eV bandgap. These experimental and model results provide more microscopic details of doped InP, which can motivate theoretically exact control of guest ion stoichiometry with optimized characteristics for electrical devices.
Collapse
Affiliation(s)
- Xian Wei
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Qi Zhang
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Zhongjie Cui
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Dan Yang
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Shiliang Mei
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Wanlu Zhang
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Haijiao Xie
- Hangzhou Yanqu Information Technology Co., Ltd., Y2, 2nd Floor, Building 2, Xixi Legu Creative Pioneering Park, No. 712 Wen'er West Road, Hangzhou 310003, China
| | - Kehan Yu
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| | - Ruiqian Guo
- Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China
- Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
- Zhongshan-Fudan Joint Innovation Center, Zhongshan 528437, China
- Yiwu Research Institute of Fudan University, Yiwu 322000, China
| | - Wei Wei
- College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China
| |
Collapse
|
2
|
Güleroğlu G, Ünlü C. Spectroscopic investigation of defect-state emission in CdSe quantum dots. Turk J Chem 2021; 45:520-527. [PMID: 34385848 PMCID: PMC8326488 DOI: 10.3906/kim-2101-66] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 02/25/2021] [Indexed: 12/25/2022] Open
Abstract
CdSe quantum dots are the most studied Cd-based quantum dots with their high quantum yield, high photostability, narrow emission band, and easy synthesis procedure. They are frequently used to develop light emitting diode (LED) due to their unique photophysical properties; however, their narrow emission band causes a challenge to design white LEDs because white light emission requires emission in multiple wavelengths with broad emission bands. Here in this study, we developed CdSe quantum dots with a narrow band-edge emission band and broad defect-state emission band through a modified two-phase synthesis method. Our results revealed that defect-state emission is directly linked to the surface of quantum dots and can be excited through exciting surfactant around the quantum dot. The effect of surfactant on emission properties of CdSe quantum dots diminished upon growing a shell around CdSe quantum dots; as a result, surface-dependent defect-state emission cannot be observed in gradient heterogeneous alloyed CdSxSe1-x quantum dots.
Collapse
Affiliation(s)
- Gülhan Güleroğlu
- Department of Chemistry, Faculty of Arts and Science, İstanbul Technical University, İstanbul Turkey
| | - Caner Ünlü
- Department of Chemistry, Faculty of Arts and Science, İstanbul Technical University, İstanbul Turkey.,Department of Nanoscience and Nanoengineering, İstanbul Technical University, İstanbul Turkey.,İstanbul Technical University Nanotechnology Research and Application Center (ITUNano), İstanbul Technical University, İstanbul Turkey
| |
Collapse
|
3
|
Sawetwong P, Chairam S, Jarujamrus P, Amatatongchai M. Enhanced selectivity and sensitivity for colorimetric determination of glyphosate using Mn-ZnS quantum dot embedded molecularly imprinted polymers combined with a 3D-microfluidic paper-based analytical device. Talanta 2021; 225:122077. [PMID: 33592801 DOI: 10.1016/j.talanta.2020.122077] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/28/2020] [Accepted: 12/29/2020] [Indexed: 01/06/2023]
Abstract
We report a novel three-dimensional microfluidic paper-based analytical device (3D-μPAD) with colorimetric detection, using Mn-ZnS quantum dot embedded molecularly imprinted polymer (Mn-ZnS QD-MIP), for selective glyphosate determination in whole grain samples. Detection is based on the catalytic activity of Mn-ZnS QD-MIP in the H2O2 oxidation of ABTS. Glyphosate imprinted polymer is successfully synthesized on the Mn-ZnS QD surface using a poly (N-isopropylacrylamide) (NIPAM) and N, N'-Methylenebisacrylamide (MBA) as the functional monomers. The catalytic activity depends on binding or non-binding of glyphosate molecules on the synthetic recognition sites of the Mn-ZnS QD-MIP. Glyphosate selectively binds to the cavities embedded on the Mn-ZnS QD surface, and subsequently turns-off or inhibits the ABTS oxidation and color change to light green. The change of reaction color from dark green to light green depends on the concentration of glyphosate. We report, for the first time, using the relatively new penguard enamel colour to create a hydrophobic barrier. The foldable 3D-μPAD comprises three layers (top/center/bottom), named as the detection zone, immobilized Mn-ZnS QD-MIP disc, and sample loading. Assay on the 3D-μPAD can determine glyphosate by ImageJ detection, over an operating range of 0.005-50 μg mL-1 and with a detection limit of 0.002 μg mL-1. Our 3D-μPAD exhibits high accuracy, with a 0.4% (intra-day) and 0.7% (inter-day) relative difference from the certified CRM value. Moreover, the fabricated 3D-μPAD provides good reproducibility (1.7% RSD for ten devices). The developed 3D-μPAD was successfully applied to determine the glyphosate concentration in whole grain samples and shows great promise as an alternative highly selective and sensitive colorimetric method. The 3D-μPAD is well suited to food-quality control and onsite environmental-monitoring applications, without sophisticated instrumentation.
Collapse
Affiliation(s)
- Pornchanok Sawetwong
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand; Nanomaterials Science, Sensors & Catalysis for Problem-Based Projects, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand
| | - Sanoe Chairam
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand; Nanomaterials Science, Sensors & Catalysis for Problem-Based Projects, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand
| | - Purim Jarujamrus
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand; Nanomaterials Science, Sensors & Catalysis for Problem-Based Projects, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand
| | - Maliwan Amatatongchai
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand; Nanomaterials Science, Sensors & Catalysis for Problem-Based Projects, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand.
| |
Collapse
|
4
|
Granada-Ramirez D, Arias-Cerón J, Pérez-González M, Luna-Arias J, Cruz-Orea A, Rodríguez-Fragoso P, Herrera-Pérez J, Gómez-Herrera M, Tomás S, Vázquez-Hernández F, Durán-Ledezma A, Mendoza-Alvarez J. Chemical synthesis and optical, structural, and surface characterization of InP-In 2O 3 quantum dots. APPLIED SURFACE SCIENCE 2020; 530:147294. [PMID: 32834267 PMCID: PMC7375344 DOI: 10.1016/j.apsusc.2020.147294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 06/11/2020] [Accepted: 07/15/2020] [Indexed: 05/14/2023]
Abstract
InP-In2O3 colloidal quantum dots (QDs) synthesized by a single-step chemical method without injection of hot precursors (one-pot) were investigated. Specifically, the effect of the tris(trimethylsilyl)phosphine, P(TMS)3, precursor concentration on the QDs properties was studied to effectively control the size and shape of the samples with a minimum size dispersion. The effect of the P(TMS)3 precursor concentration on the optical, structural, chemical surface, and electronic properties of InP-In2O3 QDs is discussed. The absorption spectra of InP-In2O3 colloids, obtained by both UV-Vis spectrophotometry and photoacoustic spectroscopy, showed a red-shift in the high-energy regime as the concentration of the P(TMS)3 increased. In addition, these results were used to determine the band-gap energy of the InP-In2O3 nanoparticles, which changed between 2.0 and 2.9 eV. This was confirmed by Photoluminescence spectroscopy, where a broad-band emission displayed from 2.0 to 2.9 eV is associated with the excitonic transition of the InP and In2O3 QDs. In2O3 and InP QDs with diameters ranging approximately from 8 to 10 nm and 6 to 9 nm were respectively found by HR-TEM. The formation of the InP and In2O3 phases was confirmed by X-ray Photoelectron Spectroscopy.
Collapse
Affiliation(s)
- D.A. Granada-Ramirez
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - J.S. Arias-Cerón
- Cátedra CONACYT-Departamento de Ingeniería Eléctrica, Sección de Electrónica del Estado Sólido, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - M. Pérez-González
- Área Académica de Matemáticas y Física, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km. 4.5, Col. Carboneras, C.P. 42184, Mineral de la Reforma, Hidalgo, Mexico
- Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas del I.P.N., Av. Instituto Politécnico Nacional, Col. San Pedro Zacatenco, C.P. 07340 Ciudad de México, Mexico
| | - J.P. Luna-Arias
- Departamento de Biología Celular, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
- Programa de Doctorado de Nanociencias y Nanotecnología, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - A. Cruz-Orea
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - P. Rodríguez-Fragoso
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - J.L. Herrera-Pérez
- Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas del I.P.N., Av. Instituto Politécnico Nacional, Col. San Pedro Zacatenco, C.P. 07340 Ciudad de México, Mexico
| | - M.L. Gómez-Herrera
- Facultad de Ingeniería, Universidad Autónoma de Querétaro, Centro Universitario, Cerro de las Campanas S/N, C.P. 76010 Santiago de Querétaro, Querétaro, Mexico
| | - S.A. Tomás
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - F. Vázquez-Hernández
- Universidad del Ejército y Fuerza Aérea, Escuela Militar de Ingenieros, Av. Industria Militar 261, Campo Militar No. 1-K, Lomas de San Isidro, Naucalpan, Edo. de México, Mexico
- Universidad Autónoma de la Ciudad de México, Av. La Corona 320, Col. Loma de la Palma, C.P. 07160 Ciudad de México, Mexico
| | - A.A. Durán-Ledezma
- Escuela Superior de Cómputo, Instituto Politécnico Nacional, Av. Juan de Dios Bátiz, esq. Av. Miguel Othón de Mendizábal, Col. Lindavista, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México, Mexico
| | - J.G. Mendoza-Alvarez
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
- Corresponding author.
| |
Collapse
|
5
|
Granada-Ramirez DA, Arias-Cerón JS, Pérez-González M, Luna-Arias JP, Cruz-Orea A, Rodríguez-Fragoso P, Herrera-Pérez JL, Gómez-Herrera ML, Tomás SA, Vázquez-Hernández F, Durán-Ledezma AA, Mendoza-Alvarez JG. Chemical synthesis and optical, structural, and surface characterization of InP-In 2O 3 quantum dots. APPLIED SURFACE SCIENCE 2020; 530:147294. [PMID: 32834267 DOI: 10.1016/j.apsusc.2020.147224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 06/11/2020] [Accepted: 07/15/2020] [Indexed: 05/24/2023]
Abstract
InP-In2O3 colloidal quantum dots (QDs) synthesized by a single-step chemical method without injection of hot precursors (one-pot) were investigated. Specifically, the effect of the tris(trimethylsilyl)phosphine, P(TMS)3, precursor concentration on the QDs properties was studied to effectively control the size and shape of the samples with a minimum size dispersion. The effect of the P(TMS)3 precursor concentration on the optical, structural, chemical surface, and electronic properties of InP-In2O3 QDs is discussed. The absorption spectra of InP-In2O3 colloids, obtained by both UV-Vis spectrophotometry and photoacoustic spectroscopy, showed a red-shift in the high-energy regime as the concentration of the P(TMS)3 increased. In addition, these results were used to determine the band-gap energy of the InP-In2O3 nanoparticles, which changed between 2.0 and 2.9 eV. This was confirmed by Photoluminescence spectroscopy, where a broad-band emission displayed from 2.0 to 2.9 eV is associated with the excitonic transition of the InP and In2O3 QDs. In2O3 and InP QDs with diameters ranging approximately from 8 to 10 nm and 6 to 9 nm were respectively found by HR-TEM. The formation of the InP and In2O3 phases was confirmed by X-ray Photoelectron Spectroscopy.
Collapse
Affiliation(s)
- D A Granada-Ramirez
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - J S Arias-Cerón
- Cátedra CONACYT-Departamento de Ingeniería Eléctrica, Sección de Electrónica del Estado Sólido, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - M Pérez-González
- Área Académica de Matemáticas y Física, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km. 4.5, Col. Carboneras, C.P. 42184, Mineral de la Reforma, Hidalgo, Mexico
- Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas del I.P.N., Av. Instituto Politécnico Nacional, Col. San Pedro Zacatenco, C.P. 07340 Ciudad de México, Mexico
| | - J P Luna-Arias
- Departamento de Biología Celular, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
- Programa de Doctorado de Nanociencias y Nanotecnología, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - A Cruz-Orea
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - P Rodríguez-Fragoso
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - J L Herrera-Pérez
- Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas del I.P.N., Av. Instituto Politécnico Nacional, Col. San Pedro Zacatenco, C.P. 07340 Ciudad de México, Mexico
| | - M L Gómez-Herrera
- Facultad de Ingeniería, Universidad Autónoma de Querétaro, Centro Universitario, Cerro de las Campanas S/N, C.P. 76010 Santiago de Querétaro, Querétaro, Mexico
| | - S A Tomás
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| | - F Vázquez-Hernández
- Universidad del Ejército y Fuerza Aérea, Escuela Militar de Ingenieros, Av. Industria Militar 261, Campo Militar No. 1-K, Lomas de San Isidro, Naucalpan, Edo. de México, Mexico
- Universidad Autónoma de la Ciudad de México, Av. La Corona 320, Col. Loma de la Palma, C.P. 07160 Ciudad de México, Mexico
| | - A A Durán-Ledezma
- Escuela Superior de Cómputo, Instituto Politécnico Nacional, Av. Juan de Dios Bátiz, esq. Av. Miguel Othón de Mendizábal, Col. Lindavista, Delegación Gustavo A. Madero, C.P. 07738 Ciudad de México, Mexico
| | - J G Mendoza-Alvarez
- Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 Ciudad de México, Mexico
| |
Collapse
|
6
|
Wei X, Mei S, Yang B, Chen Z, Dai H, Hu Z, Zhang G, Xie F, Zhang W, Guo R. Optical and Morphological Properties of Single-Phased and Dual-Emissive InP/ZnS Quantum Dots via Transition Metallic and Inorganic Ions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:10244-10250. [PMID: 32787042 DOI: 10.1021/acs.langmuir.0c01788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Single-phased and dual-emissive nanocrystals with broad emission are attractive fluorescent materials for optoelectronic devices due to their unique properties. Until now, the effect of different metallic cations and inorganic anions on III-V group quantum dots (QDs) concerning luminescence features and crystalline growth has been less explored. In this work, dual-emissive InP/ZnS QDs single-doped with transition-metal compounds (Cu2+, Ag+, or Mn2+) are synthesized to compare their optical and morphological properties. The corresponding doping concentrations to realize dual emission with comparative intensity for Cu, Ag, and Mn are 0.8, 6, and 80%, which vary greatly and might be attributed to different precursor reactivities. As for the morphological and internal structures, transmission electron microscopy (TEM) images indicate that transition-metal ions have no obvious effect on the morphological properties and a higher concentration of chloride anions binding with an In-rich interface could conduce to a homogeneous distribution and triangular growth through the comparison of different metal chlorides as precursors. X-ray photoelectron spectroscopy (XPS) results further demonstrate that the high-resolution In 3d spectrum of Mn-doped InP/ZnS QDs with MnCl2 is mainly dominated by In-P bonds, indicating fewer intermediate chemical states. These results concerning well-defined InP/ZnS QDs could promote more diverse insight into surface chemistry and help to better understand the growth mechanism, thus making it possible to regulate InP/ZnS QDs into desired formats for different practical applications like white light-emitting diodes (LEDs).
Collapse
Affiliation(s)
- Xian Wei
- Institute for Electric Light Sources, Fudan University, Shanghai 200433, China
| | - Shiliang Mei
- Institute for Electric Light Sources, Fudan University, Shanghai 200433, China
- Institute of Applied Physics and Materials Engineering, University of Macau, Macau 999078, China
| | - Bobo Yang
- Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | - Zhihao Chen
- Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | - Hanqing Dai
- Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| | - Zhe Hu
- Institute for Electric Light Sources, Fudan University, Shanghai 200433, China
| | - Guilin Zhang
- Institute for Electric Light Sources, Fudan University, Shanghai 200433, China
| | - Fengxian Xie
- Institute for Electric Light Sources, Fudan University, Shanghai 200433, China
| | - Wanlu Zhang
- Institute for Electric Light Sources, Fudan University, Shanghai 200433, China
| | - Ruiqian Guo
- Institute for Electric Light Sources, Fudan University, Shanghai 200433, China
- Academy for Engineering and Technology, Fudan University, Shanghai 200433, China
| |
Collapse
|
7
|
Tarasek S, Chou WC, Fan WC, Thomay T. Excitation power dependent Coulomb induced recombination dynamics in magnetically doped type-II quantum dots. NANO EXPRESS 2020. [DOI: 10.1088/2632-959x/ab86d9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
We observe that the wavefunction overlap of the carriers in type-II quantum dots (QDs) can be controlled by magnetic doping and strongly depends on the excitation power density. We study two different II-VI magnetic systems; ZnTe/(Zn, Mn)Se QDs with magnetic dopants in the matrix surrounding the dots, and (Zn, Mn)Te/ZnSe QDs doped in the dot core. Both magnetic systems, regardless of the location of the dopant magnetic ions, show a stark contrast in their emission with high excitation power densities (P
ex) when compared to nonmagnetic ZnTe/ZnSe QDs. Using time-resolved photoluminescence (TRPL), we observe a saturation in the blue shift for the magnetic systems at a lower P
ex, while additionally exhibiting a limited lifetime shortening over the entire range of P
ex, when compared to the nonmagnetic QDs. The results for the two magnetic systems are very similar, showing no dependence on the location of the magnetic impurities. This suggests that the behavior observed is an effect of the magnetic polaron on the band bending in the high P
ex regime. The ability to use magnetic ions to quickly saturate the charge concentration and control band bending in QDs could potentially aid in optimizing optoelectronic devices which are sensitive to high charge variations.
Collapse
|
8
|
Yadav AN, Singh AK, Chauhan D, Solanki PR, Kumar P, Singh K. Evaluation of dopant energy and Stokes shift in Cu-doped CdS quantum dots via spectro-electrochemical probing. NEW J CHEM 2020. [DOI: 10.1039/d0nj03004j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Copper (Cu) doped II–VI semiconductor quantum dots (QDs) manifest high luminescent dopant emission with excellent tunability.
Collapse
Affiliation(s)
- Amar Nath Yadav
- School of Physical Sciences
- Jawaharlal Nehru University
- New Delhi-110067
- India
| | | | - Deepika Chauhan
- Special Centre for Nanoscience
- Jawaharlal Nehru University
- New Delhi-110067
- India
| | - Pratima R. Solanki
- Special Centre for Nanoscience
- Jawaharlal Nehru University
- New Delhi-110067
- India
| | | | - Kedar Singh
- School of Physical Sciences
- Jawaharlal Nehru University
- New Delhi-110067
- India
| |
Collapse
|
9
|
Parobek D, Qiao T, Son DH. Energetic hot electrons from exciton-to-hot electron upconversion in Mn-doped semiconductor nanocrystals. J Chem Phys 2019; 151:120901. [PMID: 31575181 DOI: 10.1063/1.5119398] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Generation of hot electrons and their utilization in photoinduced chemical processes have been the subjects of intense research in recent years mostly exploring hot electrons in plasmonic metal nanostructures created via decay of optically excited plasmon. Here, we present recent progress made in generation and utilization of a different type of hot electrons produced via biphotonic exciton-to-hot electron "upconversion" in Mn-doped semiconductor nanocrystals. Compared to the plasmonic hot electrons, those produced via biphotonic upconversion in Mn-doped semiconductor nanocrystals possess much higher energy, enabling more efficient long-range electron transfer across the high energy barrier. They can even be ejected above the vacuum level creating photoelectrons, which can possibly produce solvated electrons. Despite the biphotonic nature of the upconversion process, hot electrons can be generated with weak cw excitation equivalent to the concentrated solar radiation without requiring intense or high-energy photons. This perspective reviews recent work elucidating the mechanism of generating energetic hot electrons in Mn-doped semiconductor nanocrystals, detection of these hot electrons as photocurrent or photoelectron emission, and their utilization in chemical processes such as photocatalysis. New opportunities that the energetic hot electrons can open by creating solvated electrons, which can be viewed as the longer-lived and mobile version of hot electrons more useful for chemical processes, and the challenges in practical utilization of energetic hot electrons are also discussed.
Collapse
Affiliation(s)
- David Parobek
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Tian Qiao
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Dong Hee Son
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| |
Collapse
|
10
|
Wei X, Mei S, Yang D, Zhang G, Xie F, Zhang W, Guo R. Surface States Induced Photoluminescence Enhancement of Nitrogen-Doped Carbon Dots Via Post-Treatments. NANOSCALE RESEARCH LETTERS 2019; 14:172. [PMID: 31127418 PMCID: PMC6534678 DOI: 10.1186/s11671-019-3008-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 05/07/2019] [Indexed: 05/30/2023]
Abstract
The tunable photoluminescence (PL) of nitrogen-doped carbon dots (NCDs) has attracted much attention in recent years while the specific mechanism is still in dispute. Herein, NCDs with yellow emission were successfully synthesized via a facile hydrothermal approach. Three kinds of post-treatment routes were investigated to verify the influence of surface states on the PL emission of NCDs including solvent-dependent, reduced-reaction and metal-enhanced effect. The interaction mechanism was studied by absorption spectrum, structural characterizations, steady-state and time-resolved spectroscopy. When dispersed in different solvents, the as-prepared NCDs show tunable emission and PL enhancement attributed to hydrogen bonding between solvents and NCDs. Besides, the addition of NaBH4 can induce the reduction of the C=O bonds existing in original NCDs to C-O bonds and thus result in the enhancement of the intrinsic (n-π*) emission. Moreover, metal-enhanced fluorescence of NCDs can also be observed when adding Ag+ into initial NCD solution, which might be ascribed to aggregation-induced emission enhancement. These results for post-treated NCDs demonstrate that surface functional groups are responsible for PL emission and provide new possibilities like multi-image sensing and lighting application.
Collapse
Affiliation(s)
- Xian Wei
- Engineering Research Center of Advanced Lighting Technology, Ministry of Education; Institute for Electric Light Sources, Fudan University, Shanghai, 200433 China
| | - Shiliang Mei
- Engineering Research Center of Advanced Lighting Technology, Ministry of Education; Institute for Electric Light Sources, Fudan University, Shanghai, 200433 China
| | - Dan Yang
- Engineering Research Center of Advanced Lighting Technology, Ministry of Education; Institute for Electric Light Sources, Fudan University, Shanghai, 200433 China
| | - Guilin Zhang
- Engineering Research Center of Advanced Lighting Technology, Ministry of Education; Institute for Electric Light Sources, Fudan University, Shanghai, 200433 China
| | - Fengxian Xie
- Engineering Research Center of Advanced Lighting Technology, Ministry of Education; Institute for Electric Light Sources, Fudan University, Shanghai, 200433 China
| | - Wanlu Zhang
- Engineering Research Center of Advanced Lighting Technology, Ministry of Education; Institute for Electric Light Sources, Fudan University, Shanghai, 200433 China
| | - Ruiqian Guo
- Engineering Research Center of Advanced Lighting Technology, Ministry of Education; Institute for Electric Light Sources, Fudan University, Shanghai, 200433 China
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433 China
| |
Collapse
|