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Kim J, Roh J, Park M, Lee C. Recent Advances and Challenges of Colloidal Quantum Dot Light-Emitting Diodes for Display Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2212220. [PMID: 36853911 DOI: 10.1002/adma.202212220] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Colloidal quantum dots (QDs) exhibit tremendous potential in display technologies owing to their unique optical properties, such as size-tunable emission wavelength, narrow spectral linewidth, and near-unity photoluminescence quantum yield. Significant efforts in academia and industry have achieved dramatic improvements in the performance of quantum dot light-emitting diodes (QLEDs) over the past decade, primarily owing to the development of high-quality QDs and optimized device architectures. Moreover, sophisticated patterning processes have also been developed for QDs, which is an essential technique for their commercialization. As a result of these achievements, some QD-based display technologies, such as QD enhancement films and QD-organic light-emitting diodes, have been successfully commercialized, confirming the superiority of QDs in display technologies. However, despite these developments, the commercialization of QLEDs is yet to reach a threshold, requiring a leap forward in addressing challenges and related problems. Thus, representative research trends, progress, and challenges of QLEDs in the categories of material synthesis, device engineering, and fabrication method to specify the current status and development direction are reviewed. Furthermore, brief insights into the factors to be considered when conducting research on single-device QLEDs are provided to realize active matrix displays. This review guides the way toward the commercialization of QLEDs.
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Affiliation(s)
- Jaehoon Kim
- Department of Energy and Mineral Resources Engineering, Dong-A University, Busan, 49315, Republic of Korea
| | - Jeongkyun Roh
- Department of Electrical Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Myoungjin Park
- Display Research Center, Samsung Display Co., Yongin-si, Gyeonggi-do, 17113, Republic of Korea
| | - Changhee Lee
- Display Research Center, Samsung Display Co., Yongin-si, Gyeonggi-do, 17113, Republic of Korea
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2
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Lee YJ, Kim S, Lee J, Cho E, Won YH, Kim T, Kim D. Crystallographic and Photophysical Analysis on Facet-Controlled Defect-Free Blue-Emitting Quantum Dots. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2311719. [PMID: 38214475 DOI: 10.1002/adma.202311719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/21/2023] [Indexed: 01/13/2024]
Abstract
The burgeoning demand for commercializing self-luminescing quantum dot (QD) light-emitting diodes (LEDs) has stimulated extensive research into environmentally friendly and efficient QD materials. Hydrofluoric acid (HF) additive improves photoluminescence (PL) properties of blue-emitting ZnSeTe QDs, ultimately reaching a remarkable quantum yield (QY) of 97% with an ultranarrow peak width of 14 nm after sufficient HF addition. The improvement in optical properties of the QDs is accompanied by a morphology change of the particles, forming cubic-shaped defect-free ZnSeTe QDs characterized by a zinc blende (ZB) crystal structure. This treatment improves the QD-emitting properties by facilitating facet-specific growth, selectively exposing stabilized (100) facets, and reducing the lattice disorders. The facet-specific growth process gives rise to defect-free monodispersed cubic dots that exhibit remarkably narrow and homogeneous PL spectra. Meticulous time-resolved spectroscopic studies allow an understanding of the correlation between ZnSeTe QDs' particle shape and performance following HF addition. These investigations shed light on the intricacies of the growth mechanism and the factors influencing the PL efficiency of the resulting QDs. The findings significantly contribute to understanding the role of HF treatment in tailoring the optical properties of ZnSeTe QDs, thereby bringing it closer to the realization of highly efficient and bright QD-LEDs for various practical applications.
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Affiliation(s)
- Yu Jin Lee
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 03722, South Korea
| | - Sungwoo Kim
- Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, 16678, South Korea
| | - Junho Lee
- Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, 16678, South Korea
| | - Eunseog Cho
- CSE Team, Samsung Electronics, Hwaseong, 18848, South Korea
| | - Yu-Ho Won
- Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, 16678, South Korea
| | - Taehyung Kim
- Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, 16678, South Korea
| | - Dongho Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul, 03722, South Korea
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3
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Chen Y, Wang R, Kuang Y, Bian Y, Chen F, Shen H, Chi Z, Ran X, Guo L. Suppressed Auger recombination and enhanced emission of InP/ZnSe/ZnS quantum dots through inner shell manipulation. NANOSCALE 2023; 15:18920-18927. [PMID: 37975758 DOI: 10.1039/d3nr05010f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Understanding the influence of the inner shell on fluorescence blinking and exciton dynamics is essential to promote the optical performances of InP-based quantum dots (QDs). Here, the fluorescence blinking, exciton dynamics, second-order correlation function g2(τ), and ultrafast carrier dynamics of InP/ZnSe/ZnS QDs regulated by the inner ZnSe shell thickness varying from 2 to 7 monolayers (MLs) were systematically investigated. With an inner ZnSe shell thickness of 5 MLs, the photoluminescence quantum yield (PL QY) can reach 98% due to the suppressed blinking and increased probability of multiphoton emission. The exciton dynamics of InP/ZnSe/ZnS QDs with different inner shells indicates that two decay components of neural excitons and charged trions are competitive to affect the photon emission behavior. The probability density distributions of the ON and OFF state duration in the blinking traces demonstrate an effective manipulation of the inner ZnSe shell in the non-radiative processes via defect passivation. Accordingly, the radiative recombination dominates the exciton deactivation and the non-radiative Auger recombination rate is remarkably reduced, leading to a QY close to unity and a high PL stability for InP/ZnSe/ZnS QDs with 5 MLs of the ZnSe shell. These results provide insights into the photophysical mechanism of InP-based QDs and are significant for developing novel semiconductor PL core/shell QDs.
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Affiliation(s)
- Yaru Chen
- School of Physics and Electronics, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, Henan University, Kaifeng, 475004, China.
| | - Rixin Wang
- School of Physics and Electronics, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, Henan University, Kaifeng, 475004, China.
| | - Yanmin Kuang
- School of Physics and Electronics, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, Henan University, Kaifeng, 475004, China.
| | - Yangyang Bian
- Key Laboratory for Special Functional Materials of Ministry of Education National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng, 475004, P. R. China
| | - Fei Chen
- Key Laboratory for Special Functional Materials of Ministry of Education National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng, 475004, P. R. China
| | - Huaibin Shen
- Key Laboratory for Special Functional Materials of Ministry of Education National & Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng, 475004, P. R. China
| | - Zhen Chi
- School of Physics and Electronics, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, Henan University, Kaifeng, 475004, China.
| | - Xia Ran
- School of Physics and Electronics, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, Henan University, Kaifeng, 475004, China.
| | - Lijun Guo
- School of Physics and Electronics, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, Henan University, Kaifeng, 475004, China.
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4
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Nguyen HA, Dixon G, Dou FY, Gallagher S, Gibbs S, Ladd DM, Marino E, Ondry JC, Shanahan JP, Vasileiadou ES, Barlow S, Gamelin DR, Ginger DS, Jonas DM, Kanatzidis MG, Marder SR, Morton D, Murray CB, Owen JS, Talapin DV, Toney MF, Cossairt BM. Design Rules for Obtaining Narrow Luminescence from Semiconductors Made in Solution. Chem Rev 2023. [PMID: 37311205 DOI: 10.1021/acs.chemrev.3c00097] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Solution-processed semiconductors are in demand for present and next-generation optoelectronic technologies ranging from displays to quantum light sources because of their scalability and ease of integration into devices with diverse form factors. One of the central requirements for semiconductors used in these applications is a narrow photoluminescence (PL) line width. Narrow emission line widths are needed to ensure both color and single-photon purity, raising the question of what design rules are needed to obtain narrow emission from semiconductors made in solution. In this review, we first examine the requirements for colloidal emitters for a variety of applications including light-emitting diodes, photodetectors, lasers, and quantum information science. Next, we will delve into the sources of spectral broadening, including "homogeneous" broadening from dynamical broadening mechanisms in single-particle spectra, heterogeneous broadening from static structural differences in ensemble spectra, and spectral diffusion. Then, we compare the current state of the art in terms of emission line width for a variety of colloidal materials including II-VI quantum dots (QDs) and nanoplatelets, III-V QDs, alloyed QDs, metal-halide perovskites including nanocrystals and 2D structures, doped nanocrystals, and, finally, as a point of comparison, organic molecules. We end with some conclusions and connections, including an outline of promising paths forward.
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Affiliation(s)
- Hao A Nguyen
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Grant Dixon
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Florence Y Dou
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Shaun Gallagher
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Stephen Gibbs
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Dylan M Ladd
- Department of Materials Science and Engineering, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Emanuele Marino
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Via Archirafi 36, 90123 Palermo, Italy
| | - Justin C Ondry
- Department of Chemistry, James Franck Institute, and Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - James P Shanahan
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Eugenia S Vasileiadou
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Stephen Barlow
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - David S Ginger
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - David M Jonas
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Mercouri G Kanatzidis
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Seth R Marder
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Daniel Morton
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Christopher B Murray
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jonathan S Owen
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Dmitri V Talapin
- Department of Chemistry, James Franck Institute, and Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Michael F Toney
- Department of Materials Science and Engineering, University of Colorado Boulder, Boulder, Colorado 80303, United States
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, Colorado 80303, United States
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80303, United States
| | - Brandi M Cossairt
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
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Du R, Li X, Li Y, Li Y, Hou T, Li Y, Qiao C, Zhang J. Cation Exchange Synthesis of Aliovalent Doped InP QDs and Their ZnSe xS 1-x Shell Coating for Enhanced Fluorescence Properties. J Phys Chem Lett 2023; 14:670-676. [PMID: 36637473 DOI: 10.1021/acs.jpclett.2c03515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
III-V quantum dots (QDs), in particular InP QDs, have emerged as high-performance and environmentally friendly candidates to replace cadmium based QDs. InP QDs exhibit properties of direct band gap structure, low toxicity, and high mobility, which make them suitable for high-performance optoelectronic applications. However, it is still challenging to precisely regulate the components and crystal structure of InP QDs, especially in the engineered stable aliovalent doping. In this work, we developed our original reverse cation exchange strategy to achieve Cu+ doped InP (InP:Cu) QDs at lower temperature. A ZnSexS1-x shell was then homogeneously grown on the InP:Cu QDs as the passivation shell. The as-prepared InP:Cu@ZnSexS1-x core-shell QDs exhibited better fluorescence properties with a photoluminescence quantum yield (PLQY) of 56.47%. Due to the existence of multiple luminous centers in the QDs, variable temperature-dependent fluorescence characteristics have been studied. The high photoluminescence characteristics in the near-infrared region indicate their potential applications in optoelectronic devices and biological fields.
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Affiliation(s)
- Ruizhi Du
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xinyuan Li
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - You Li
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yuxi Li
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Tailei Hou
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yuemei Li
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Chen Qiao
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Jiatao Zhang
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Key Laboratory of Medical Molecule Science and Pharmaceutical Engineering, Ministry of Industry and Information Technology, MOE Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
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6
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Manoj B, Somasundaran SM, Rajan D, Thirunavukkuarasu S, Thomas KG. InP-Bovine Serum Albumin Conjugates as Energy Transfer Probes. J Phys Chem B 2022; 126:2635-2646. [PMID: 35353512 DOI: 10.1021/acs.jpcb.1c10134] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The use of indium phosphide (InP) quantum dots (QDs) as biological fluorophores is limited by the low photoluminescence quantum yield (ϕPL) and the lack of effective bioconjugation strategies. The former issue has been addressed by introducing a strain relaxing intermediate shell such as ZnSe, GaP etc. that significantly enhances the ϕPL of InP. Herein, we present an effective strategy for the conjugation of emissive InP/GaP/ZnS QDs with a commonly used globular protein, namely bovine serum albumin (BSA), which generate colloidally stable QD bioconjugates, labeled as InP-BSA and demonstrate its use as energy transfer probes. The conjugate contains one protein per QD, and the circular dichroism spectra of BSA and InP-BSA exhibit similar fractions of α-helix and β-sheet, reflective of the fact that the secondary structure of the protein is intact on binding. More importantly, the fluorescence polarization studies corroborate the fact that the bound protein can hold a variety of chromophoric acceptors. Upon selectively exciting the InP-BSA component in the presence of bound chromophores, a reduction in the emission intensity of the donor is observed with a concomitant increase in emission of the acceptor. Time-resolved investigations further confirm an efficient nonradiative energy transfer from InP-BSA to the bound acceptors.
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Affiliation(s)
- Bhaskaran Manoj
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
| | - Sanoop Mambully Somasundaran
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
| | - Devika Rajan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
| | - Shyamala Thirunavukkuarasu
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
| | - K George Thomas
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
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7
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Lee Y, Jo DY, Kim T, Jo JH, Park J, Yang H, Kim D. Effectual Interface and Defect Engineering for Auger Recombination Suppression in Bright InP/ZnSeS/ZnS Quantum Dots. ACS APPLIED MATERIALS & INTERFACES 2022; 14:12479-12487. [PMID: 35238532 DOI: 10.1021/acsami.1c20088] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The main issue in developing a quantum dot light-emitting diode (QLED) display lies in successfully replacing heavy metals with environmentally benign materials while maintaining high-quality device performance. Nonradiative Auger recombination is one of the major limiting factors of QLED performance and should ideally be suppressed. This study scrutinizes the effects of the shell structure and composition on photoluminescence (PL) properties of InP/ZnSeS/ZnS quantum dots (QDs) through ensemble and single-dot spectroscopic analyses. Employing gradient shells is discovered to suppress Auger recombination to a high degree, allowing charged QDs to be luminescent comparatively with neutral QDs. The "lifetime blinking" phenomenon is observed as evidence of suppressed Auger recombination. Furthermore, single-QD measurements reveal that gradient shells in QDs reduce spectral diffusion and elevate the energy barrier for charge trapping. Shell composition dependency in the gradience effect is observed. An increase in the ZnS composition (ZnS >50%) in the gradient shell introduces lattice mismatch between the core and the shell and therefore rather reverses the effect and reduces the QD performance.
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Affiliation(s)
- YuJin Lee
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Dae-Yeon Jo
- Department of Materials Science and Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of Korea
| | - Taehee Kim
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Jung-Ho Jo
- Department of Materials Science and Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of Korea
| | - Jumi Park
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Heesun Yang
- Department of Materials Science and Engineering, Hongik University, 94 Wausan-ro, Mapo-gu, Seoul 04066, Republic of Korea
| | - Dongho Kim
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea
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8
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Kang S, Han S, Kang Y. First-Principles Calculations of Luminescence Spectra of Real-Scale Quantum Dots. ACS MATERIALS AU 2021; 2:103-109. [PMID: 36855768 PMCID: PMC9888616 DOI: 10.1021/acsmaterialsau.1c00034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The luminescence line shape is an important feature of semiconductor quantum dots (QDs) and affects performance in various optical applications. Here, we report a first-principles method to predict the luminescence spectrum of thousands of atom QDs. In our approach, neural network potential calculations are combined with density functional theory calculations to describe exciton-phonon coupling (EPC). Using the calculated EPC, the luminescence spectrum is evaluated within the Franck-Condon approximation. Our approach results in the luminescence line shape for an InP/ZnSe core/shell QD (3406 atoms) that exhibits excellent agreement with the experiments. From a detailed analysis of EPC, we reveal that the coupling of both acoustic and optical phonons to an exciton are important in determining the spectral line shapes of core/shell QDs, which is in contrast with previous studies. On the basis of the present simulation results, we provide guidelines for designing high-performance core/shell QDs with ultrasharp emission spectra.
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Affiliation(s)
- Sungwoo Kang
- Department
of Materials Science and Engineering and Research Institute of Advanced
Materials, Seoul National University, Seoul 08826, Korea
| | - Seungwu Han
- Department
of Materials Science and Engineering and Research Institute of Advanced
Materials, Seoul National University, Seoul 08826, Korea,
| | - Youngho Kang
- Department
of Materials Science and Engineering, Incheon
National University, Incheon 22012, Korea,
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9
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Zhang B, Luo Y, Mai C, Mu L, Li M, Wang J, Xu W, Peng J. Effects of ZnMgO Electron Transport Layer on the Performance of InP-Based Inverted Quantum Dot Light-Emitting Diodes. NANOMATERIALS 2021; 11:nano11051246. [PMID: 34065118 PMCID: PMC8151885 DOI: 10.3390/nano11051246] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 01/11/2023]
Abstract
An environment-friendly inverted indium phosphide red quantum dot light-emitting diode (InP QLED) was fabricated using Mg-doped zinc oxide (ZnMgO) as the electron transport layer (ETL). The effects of ZnMgO ETL on the performance of InP QLED were investigated. X-ray diffraction (XRD) analysis indicated that ZnMgO film has an amorphous structure, which is similar to zinc oxide (ZnO) film. Comparison of morphology between ZnO film and ZnMgO film demonstrated that Mg-doped ZnO film remains a high-quality surface (root mean square roughness: 0.86 nm) as smooth as ZnO film. The optical band gap and ultraviolet photoelectron spectroscopy (UPS) analysis revealed that the conduction band of ZnO shifts to a more matched position with InP quantum dot after Mg-doping, resulting in the decrease in turn-on voltage from 2.51 to 2.32 V. In addition, the ratio of irradiation recombination of QLED increases from 7% to 25% using ZnMgO ETL, which can be attributed to reduction in trap state by introducing Mg ions into ZnO lattices. As a result, ZnMgO is a promising material to enhance the performance of inverted InP QLED. This work suggests that ZnMgO has the potential to improve the performance of QLED, which consists of the ITO/ETL/InP QDs/TCTA/MoO3/Al, and Mg-doping strategy is an efficient route to directionally regulate ZnO conduction bands.
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10
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Yang W, Yang Y, Kaledin AL, He S, Jin T, McBride JR, Lian T. Surface passivation extends single and biexciton lifetimes of InP quantum dots. Chem Sci 2020; 11:5779-5789. [PMID: 32832054 PMCID: PMC7416692 DOI: 10.1039/d0sc01039a] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/15/2020] [Indexed: 01/18/2023] Open
Abstract
Indium phosphide quantum dots (InP QDs) are nontoxic nanomaterials with potential applications in photocatalytic and optoelectronic fields. Post-synthetic treatments of InP QDs are known to be essential for improving their photoluminescence quantum efficiencies (PLQEs) and device performances, but the mechanisms remain poorly understood. Herein, by applying ultrafast transient absorption and photoluminescence spectroscopies, we systematically investigate the dynamics of photogenerated carriers in InP QDs and how they are affected by two common passivation methods: HF treatment and the growth of a heterostructure shell (ZnS in this study). The HF treatment is found to improve the PLQE up to 16-20% by removing an intrinsic fast hole trapping channel (τ h,non = 3.4 ± 1 ns) in the untreated InP QDs while having little effect on the band-edge electron decay dynamics (τ e = 26-32 ns). The growth of the ZnS shell, on the other hand, is shown to improve the PLQE up to 35-40% by passivating both electron and hole traps in InP QDs, resulting in both a long-lived band-edge electron (τ e > 120 ns) and slower hole trapping lifetime (τ h,non > 45 ns). Furthermore, both the untreated and the HF-treated InP QDs have short biexciton lifetimes (τ xx ∼ 1.2 ± 0.2 ps). The growth of an ultra-thin ZnS shell (∼0.2 nm), on the other hand, can significantly extend the biexciton lifetime of InP QDs to 20 ± 2 ps, making it a passivation scheme that can improve both the single and multiple exciton lifetimes. Based on these results, we discuss the possible trap-assisted Auger processes in InP QDs, highlighting the particular importance of trap passivation for reducing the Auger recombination loss in InP QDs.
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Affiliation(s)
- Wenxing Yang
- Department of Chemistry , Emory University , 1515 Dickey Drive Northeast , Atlanta , Georgia 30322 , USA . ;
- Department of Chemistry - Ångström Laboratory , Physical Chemistry , Uppsala University , SE-75120 Uppsala , Sweden
| | - Yawei Yang
- Department of Chemistry , Emory University , 1515 Dickey Drive Northeast , Atlanta , Georgia 30322 , USA . ;
- Electronic Materials Research Laboratory , Key Laboratory of the Ministry of Education , International Center for Dielectric Research , Shaanxi Engineering Research Center of Advanced Energy Materials and Devices , School of Electronic Science and Engineering , Xi'an Jiaotong University , Xi'an 710049 , Shaanxi , P. R. China
| | - Alexey L Kaledin
- Cherry L. Emerson Center for Scientific Computation , Emory University , 1515 Dickey Drive , Atlanta , GA 30322 , USA
| | - Sheng He
- Department of Chemistry , Emory University , 1515 Dickey Drive Northeast , Atlanta , Georgia 30322 , USA . ;
| | - Tao Jin
- Department of Chemistry , Emory University , 1515 Dickey Drive Northeast , Atlanta , Georgia 30322 , USA . ;
| | - James R McBride
- Department of Chemistry , The Vanderbilt Institute of Nanoscale Science and Engineering , Vanderbilt University , Nashville , TN 37235 , USA
| | - Tianquan Lian
- Department of Chemistry , Emory University , 1515 Dickey Drive Northeast , Atlanta , Georgia 30322 , USA . ;
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Freymeyer NJ, Click SM, Reid KR, Chisholm MF, Bradsher CE, McBride JR, Rosenthal SJ. Effect of indium alloying on the charge carrier dynamics of thick-shell InP/ZnSe quantum dots. J Chem Phys 2020; 152:161104. [PMID: 32357779 DOI: 10.1063/1.5145189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Thick-shell InP/ZnSe III-V/II-VI quantum dots (QDs) were synthesized with two distinct interfaces between the InP core and ZnSe shell: alloy and core/shell. Despite sharing similar optical properties in the spectral domain, these two QD systems have differing amounts of indium incorporation in the shell as determined by high-resolution energy-dispersive x-ray spectroscopy scanning transmission electron microscopy. Ultrafast fluorescence upconversion spectroscopy was used to probe the charge carrier dynamics of these two systems and shows substantial charge carrier trapping in both systems that prevents radiative recombination and reduces the photoluminescence quantum yield. The alloy and core/shell QDs show slight differences in the extent of charge carrier localization with more extensive trapping observed in the alloy nanocrystals. Despite the ability to grow a thick shell, structural defects caused by III-V/II-VI charge carrier imbalances still need to be mitigated to further improve InP QDs.
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Affiliation(s)
| | - Sophia M Click
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Kemar R Reid
- Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Matthew F Chisholm
- Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - Cara E Bradsher
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - James R McBride
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Sandra J Rosenthal
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA
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