1
|
Yan X, Qian JH, Sangwan VK, Hersam MC. Progress and Challenges for Memtransistors in Neuromorphic Circuits and Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2108025. [PMID: 34813677 DOI: 10.1002/adma.202108025] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/07/2021] [Indexed: 06/13/2023]
Abstract
Due to the increasing importance of artificial intelligence (AI), significant recent effort has been devoted to the development of neuromorphic circuits that seek to emulate the energy-efficient information processing of the brain. While non-volatile memory (NVM) based on resistive switches, phase-change memory, and magnetic tunnel junctions has shown potential for implementing neural networks, additional multi-terminal device concepts are required for more sophisticated bio-realistic functions. Of particular interest are memtransistors based on low-dimensional nanomaterials, which are capable of electrostatically tuning memory and learning behavior at the device level. Herein, a conceptual overview of the memtransistor is provided in the context of neuromorphic circuits. Recent progress is surveyed for memtransistors and related multi-terminal NVM devices including dual-gated floating-gate memories, dual-gated ferroelectric transistors, and dual-gated van der Waals heterojunctions. The different materials systems and device architectures are classified based on the degree of control and relative tunability of synaptic behavior, with an emphasis on device concepts that harness the reduced dimensionality, weak electrostatic screening, and phase-changes properties of nanomaterials. Finally, strategies for achieving wafer-scale integration of memtransistors and multi-terminal NVM devices are delineated, with specific attention given to the materials challenges for practical neuromorphic circuits.
Collapse
Affiliation(s)
- Xiaodong Yan
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Justin H Qian
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Vinod K Sangwan
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Mark C Hersam
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, IL, 60208, USA
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
| |
Collapse
|
2
|
Scandurra G, Ciofi C, Smulko J, Wen H. A review of design approaches for the implementation of low-frequency noise measurement systems. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:111101. [PMID: 36461421 DOI: 10.1063/5.0116589] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/20/2022] [Indexed: 06/17/2023]
Abstract
Electronic noise has its roots in the fundamental physical interactions between matter and charged particles, carrying information about the phenomena that occur at the microscopic level. Therefore, Low-Frequency Noise Measurements (LFNM) are a well-established technique for the characterization of electron devices and materials and, compared to other techniques, they offer the advantage of being non-destructive and of providing a more detailed view of what happens in the matter during the manifestation of physical or chemical phenomena. For this reason, LFNM acquire particular importance in the modern technological era in which the introduction of new advanced materials requires in-depth and thorough characterization of the conduction phenomena. LFNM also find application in the field of sensors, as they allow to obtain more selective sensing systems even starting from conventional sensors. Performing meaningful noise measurements, however, requires that the background noise introduced by the measurement chain be much smaller than the noise to be detected and the instrumentation available on the market does not always meet the specifications required for reaching the ultimate sensitivity. Researchers willing to perform LFNM must often resort to the design of dedicated instrumentation in their own laboratories, but their cultural background does not necessarily include the ability to design, build, and test dedicated low noise instrumentation. In this review, we have tried to provide as much theoretical and practical guidelines as possible, so that even researchers with a limited background in electronic engineering can find useful information in developing or customizing low noise instrumentation.
Collapse
Affiliation(s)
- G Scandurra
- Department of Engineering, University of Messina, Messina 98166, Italy
| | - C Ciofi
- Department of Engineering, University of Messina, Messina 98166, Italy
| | - J Smulko
- Department of Metrology and Optoelectronics, Gdańsk University of Technology, 80-233 Gdańsk, Poland
| | - H Wen
- College of Electrical and Information Engineering, Hunan University, Changsha 410082, China
| |
Collapse
|
3
|
Don MF, Ekanayake P, Jennings JR, Nakajima H, Lim CM. Graphite/Carbon Black Counter Electrode Deposition Methods to Improve the Efficiency and Stability of Hole-Transport-Layer-Free Perovskite Solar Cells. ACS OMEGA 2022; 7:22830-22838. [PMID: 35811920 PMCID: PMC9260948 DOI: 10.1021/acsomega.2c02555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 06/03/2022] [Indexed: 05/16/2023]
Abstract
The interfacial compatibility between the graphite/carbon black composite counter electrode (Gr/CB CE) and the perovskite layer is a crucial determinant of the performance of the hole-transport-layer-free carbon-based perovskite solar cells, and judicious selection of the Gr/CB CE application method is essential for achieving an optimum contact. In this work, three different types of Gr/CB CEs application methods are investigated: (1) deposition of Gr/CB on the fluorine-doped tin oxide (FTO) substrate, followed by clamping to the perovskite layer, (2) direct deposition of Gr/CB onto the perovskite layer, and (3) deposition of Gr/CB onto the PbI2 precursor layer, followed by immersion in methylammonium iodide solution for the in situ conversion of PbI2 to perovskite. The results revealed that Method 3 produced superior Gr/CB-perovskite contacts, resulting in up to 8.81% power conversion efficiency. The devices prepared using Method 3 also exhibited the best stability in the air, retaining 71.1% of their original efficiency after 1600 h of continuous testing. These results demonstrate that Gr/CB CEs can be considered excellent alternatives to the costly noble metals often employed in perovskite solar cells (PSCs) when deposited using a suitable technique.
Collapse
Affiliation(s)
- Muna Fathiah Don
- Faculty
of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE 1410, Brunei Darussalam
| | - Piyasiri Ekanayake
- Faculty
of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE 1410, Brunei Darussalam
- Optoelectronic
Device Research Group, Universiti Brunei
Darussalam, Jalan Tungku
Link, Gadong BE 1410, Brunei Darussalam
| | - James Robert Jennings
- Faculty
of Science, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE 1410, Brunei Darussalam
- Optoelectronic
Device Research Group, Universiti Brunei
Darussalam, Jalan Tungku
Link, Gadong BE 1410, Brunei Darussalam
| | - Hideki Nakajima
- Synchrotron
Light Research Institute, 111 University Avenue, Muang District, Nakhon
Ratchasima 30000, Thailand
| | - Chee Ming Lim
- Centre
for Advanced Material and Energy Sciences, Universiti Brunei Darussalam, Jalan Tungku Link, Gadong BE 1410, Brunei Darussalam
| |
Collapse
|
4
|
Tailor NK, Senanayak SP, Abdi-Jalebi M, Satapathi S. Low-frequency carrier kinetics in triple cation perovskite solar cells probed by impedance and modulus spectroscopy. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138430] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
5
|
Li G, Zhang X, Jones LO, Alzola JM, Mukherjee S, Feng LW, Zhu W, Stern CL, Huang W, Yu J, Sangwan VK, DeLongchamp DM, Kohlstedt KL, Wasielewski MR, Hersam MC, Schatz GC, Facchetti A, Marks TJ. Systematic Merging of Nonfullerene Acceptor π-Extension and Tetrafluorination Strategies Affords Polymer Solar Cells with >16% Efficiency. J Am Chem Soc 2021; 143:6123-6139. [PMID: 33848146 DOI: 10.1021/jacs.1c00211] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The end-capping group (EG) is the essential electron-withdrawing component of nonfullerene acceptors (NFAs) in bulk heterojunction (BHJ) organic solar cells (OSCs). To systematically probe the impact of two frequent EG functionalization strategies, π-extension and halogenation, in A-DAD-A type NFAs, we synthesized and characterized four such NFAs: BT-BIC, LIC, L4F, and BO-L4F. To assess the relative importance of these strategies, we contrast these NFAs with the baseline acceptors, Y5 and Y6. Up to 16.6% power conversion efficiency (PCE) in binary inverted OSCs with BT-BO-L4F combining π-extension and halogenation was achieved. When these two factors are combined, the effect on optical absorption is cumulative. Single-crystal π-π stacking distances are similar for the EG strategies of π-extension. Increasing the alkyl substituent length from BT-L4F to BT-BO-L4F significantly alters the packing motif and eliminates the EG core interactions of BT-L4F. Electronic structure computations reveal some of the largest NFA π-π electronic couplings observed to date, 103.8 meV in BT-L4F and 47.5 meV in BT-BO-L4F. Computed electronic reorganization energies, 132 and 133 meV for BT-L4F and BT-BO-L4F, respectively, are also lower than Y6 (150 meV). BHJ blends show preferential π-face-on orientation, and both fluorination and π-extension increase NFA crystallinity. Femto/nanosecond transient absorption spectroscopy (fs/nsTA) and integrated photocurrent device analysis (IPDA) indicate that π-extension modifies the phase separation to enhance film ordering and carrier mobility, while fluorination suppresses unimolecular recombination. This systematic study highlights the synergistic effects of NFA π-extension and fluorination in affording efficient OSCs and provides insights into designing next-generation materials.
Collapse
Affiliation(s)
- Guoping Li
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Xiaohua Zhang
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, P.R. China
| | - Leighton O Jones
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Joaquin M Alzola
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Subhrangsu Mukherjee
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Liang-Wen Feng
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Weigang Zhu
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Tianjin Key Laboratory of Molecular Optoelectronic Sciences (TJ-MOS), Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China
| | - Charlotte L Stern
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Wei Huang
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Junsheng Yu
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, Sichuan 610054, P.R. China
| | - Vinod K Sangwan
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Dean M DeLongchamp
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Kevin L Kohlstedt
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Michael R Wasielewski
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Mark C Hersam
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - George C Schatz
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Antonio Facchetti
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Flexterra Corporation, 8025 Lamon Avenue, Skokie, Illinois 60077, United States
| | - Tobin J Marks
- Department of Chemistry, the Center for Light Energy Activated Redox Processes (LEAP), and the Materials Research Center (MRC), Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| |
Collapse
|
6
|
Abstract
Electric noise spectroscopy is a non-destructive and a very sensitive method for studying the dynamic behaviors of the charge carriers and the kinetic processes in several condensed matter systems, with no limitation on operating temperatures. This technique has been extensively used to investigate several perovskite compounds, manganese oxides (La1−xSrxMnO3, La0.7Ba0.3MnO3, and Pr0.7Ca0.3MnO3), and a double perovskite (Sr2FeMoO6), whose properties have recently attracted great attention. In this work are reported the results from a detailed electrical transport and noise characterizations for each of the above cited materials, and they are interpreted in terms of specific physical models, evidencing peculiar properties, such as quantum interference effects and charge density waves.
Collapse
|
7
|
Kumar A, Bansode U, Ogale S, Rahman A. Understanding the thermal degradation mechanism of perovskite solar cells via dielectric and noise measurements. NANOTECHNOLOGY 2020; 31:365403. [PMID: 32470953 DOI: 10.1088/1361-6528/ab97d4] [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
Long term stability is a major obstacle to the success of perovskite solar cell (PSC) photovoltaic technology. PSC performance deteriorates significantly in the presence of humidity, oxygen and exposure to UV light and heat. Here the change in charge transport properties of PSC with temperature and the associated significant drop in device performance at high temperature have been investigated. The latter is shown to be primarily due to an increase in charge carrier recombination, which impacts the open-circuit voltage. To understand the pathway of temperature-induced degradation, low-frequency 1/f noise characteristics, and the capacitance-frequency, as well as capacitance-voltage characteristics have been investigated under various conditions. The results show that at high operating temperature accumulation of ions and charge carriers at the interface increase the surface recombination. Aging experiments at different temperatures show high stability of PSCs up to temperature <70 °C, but a drastic, irreversible degradation occurs at higher temperature (≥80 °C). Low-frequency 1/f noise study revealed that the magnitude of normalized noise in degraded perovskite solar cells is four orders of magnitude higher than the pristine device. This study shows the power of low-frequency noise measurement technique as a highly sensitive non-invasive tool to study the degradation mechanism of PSCs.
Collapse
Affiliation(s)
- Ankit Kumar
- Department of Physics and Centre for Energy Science, Indian Institute of Science Education and Research (IISER)-Pune, Pune, Maharashtra 411008 India
| | | | | | | |
Collapse
|
8
|
Zhu W, Spencer AP, Mukherjee S, Alzola JM, Sangwan VK, Amsterdam SH, Swick SM, Jones LO, Heiber MC, Herzing AA, Li G, Stern CL, DeLongchamp DM, Kohlstedt KL, Hersam MC, Schatz GC, Wasielewski MR, Chen LX, Facchetti A, Marks TJ. Crystallography, Morphology, Electronic Structure, and Transport in Non-Fullerene/Non-Indacenodithienothiophene Polymer:Y6 Solar Cells. J Am Chem Soc 2020; 142:14532-14547. [PMID: 32698577 DOI: 10.1021/jacs.0c05560] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Emerging nonfullerene acceptors (NFAs) with crystalline domains enable high-performance bulk heterojunction (BHJ) solar cells. Thermal annealing is known to enhance the BHJ photoactive layer morphology and performance. However, the microscopic mechanism of annealing-induced performance enhancement is poorly understood in emerging NFAs, especially regarding competing factors. Here, optimized thermal annealing of model system PBDB-TF:Y6 (Y6 = 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3'':4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]-thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile) decreases the open circuit voltage (VOC) but increases the short circuit current (JSC) and fill factor (FF) such that the resulting power conversion efficiency (PCE) increases from 14 to 15% in the ambient environment. Here we systematically investigate these thermal annealing effects through in-depth characterizations of carrier mobility, film morphology, charge photogeneration, and recombination using SCLC, GIXRD, AFM, XPS, NEXAFS, R-SoXS, TEM, STEM, fs/ns TA spectroscopy, 2DES, and impedance spectroscopy. Surprisingly, thermal annealing does not alter the film crystallinity, R-SoXS characteristic size scale, relative average phase purity, or TEM-imaged phase separation but rather facilitates Y6 migration to the BHJ film top surface, changes the PBDB-TF/Y6 vertical phase separation and intermixing, and reduces the bottom surface roughness. While these morphology changes increase bimolecular recombination (BR) and lower the free charge (FC) yield, they also increase the average electron and hole mobility by at least 2-fold. Importantly, the increased μh dominates and underlies the increased FF and PCE. Single-crystal X-ray diffraction reveals that Y6 molecules cofacially pack via their end groups/cores, with the shortest π-π distance as close as 3.34 Å, clarifying out-of-plane π-face-on molecular orientation in the nanocrystalline BHJ domains. DFT analysis of Y6 crystals reveals hole/electron reorganization energies of as low as 160/150 meV, large intermolecular electronic coupling integrals of 12.1-37.9 meV rationalizing the 3D electron transport, and relatively high μe of 10-4 cm2 V-1 s-1. Taken together, this work clarifies the richness of thermal annealing effects in high-efficiency NFA solar cells and tasks for future materials design.
Collapse
Affiliation(s)
| | | | - Subhrangsu Mukherjee
- Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States
| | | | | | | | | | | | - Michael C Heiber
- Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States
| | - Andrew A Herzing
- Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States
| | | | | | - Dean M DeLongchamp
- Material Measurement Laboratory, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States
| | | | | | | | | | - Lin X Chen
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Antonio Facchetti
- Flexterra Corporation, 8025 Lamon Avenue, Skokie, Illinois 60077, United States
| | | |
Collapse
|
9
|
Kumar R, Kumar J, Srivastava P, Moghe D, Kabra D, Bag M. Unveiling the Morphology Effect on the Negative Capacitance and Large Ideality Factor in Perovskite Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2020; 12:34265-34273. [PMID: 32608224 DOI: 10.1021/acsami.0c04489] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Perovskite light-emitting diodes have almost reached the threshold for potential commercialization within a few years of research. However, there are still some unsolved puzzles such as large ideality factor and the presence of large negative capacitance especially at the low-frequency regime yet to be addressed. Here, we have fabricated a methylammonium lead tri-bromide perovskite n-i-p structure for light-emitting diodes from a smooth and textured emissive layer and demonstrated for the first time that these two factors are strongly dependent on the perovskite film morphology. Bias-dependent capacitance measurement also reveals the transition between negative to positive capacitance in textured films at the low-frequency regime. We have observed an anomalous capacitive behavior at the mid-frequency regime in smooth perovskite films but not in textured films. The relatively large ideality factor and anomalous capacitive behavior observed in perovskite light-emitting diodes are due to the presence of strong coupling between ions and electrons near the electrode interface. Therefore, the ideality factor and anomalous capacitance at the mid-frequency regime can be decreased by minimizing electronic-ionic coupling in textured perovskite films, while light outcoupling can be improved significantly.
Collapse
Affiliation(s)
- Ramesh Kumar
- Advanced Research in Electrochemical Impedance Spectroscopy Laboratory, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Jitendra Kumar
- Advanced Research in Electrochemical Impedance Spectroscopy Laboratory, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Priya Srivastava
- Advanced Research in Electrochemical Impedance Spectroscopy Laboratory, Indian Institute of Technology Roorkee, Roorkee 247667, India
| | - Dhanashree Moghe
- Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Dinesh Kabra
- Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Monojit Bag
- Advanced Research in Electrochemical Impedance Spectroscopy Laboratory, Indian Institute of Technology Roorkee, Roorkee 247667, India
| |
Collapse
|
10
|
Park M, Song J, An M, Lim J, Lee C, Roh J, Lee D. Colloidal quantum dot light-emitting diodes employing solution-processable tin dioxide nanoparticles in an electron transport layer. RSC Adv 2020; 10:8261-8265. [PMID: 35497858 PMCID: PMC9049948 DOI: 10.1039/d0ra00653j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 02/19/2020] [Indexed: 11/21/2022] Open
Abstract
Colloidal quantum-dot-based light-emitting diodes (QD-LEDs) have gained tremendous attention as great candidates to potentially replace current emissive display technologies. The luminescence efficiency of a QD LED has increased rapidly in the past decade; this was triggered by the use of metal oxides in the charge transport layers, particularly zinc oxide (ZnO) for the electron transport layer (ETL). However, the ZnO ETL often results in undesirable device performance such as efficiency roll-off and poor device stability because of excessive electron injection into the QD emissive layer. Here, we explore solution-processable tin dioxide (SnO2) nanoparticles (NPs) as alternatives to ZnO NPs for the ETL in QD-LEDs. We evaluated the thin-film quality and electrical performance of SnO2 NPs and then applied them to the ETL for constructing QD-LEDs. As a result of the smooth surface morphology, moderate electron-transport ability, and lower carrier concentration compared to ZnO NPs, the QD-LED with SnO2 NP-ETL exhibited improved performance in terms of lower turn-on and operating voltages, maximum luminance, improved efficiency roll-off, and improved power efficiency over the reference device with the ZnO NP-ETL. This shows promising potential for SnO2 NPs in optoelectronic applications. QD-LEDs have gained tremendous attention to potentially replace current emissive display technologies. Here, we explore solution-processable SnO2 nanoparticles (NPs) as alternatives to ZnO for the electron transporting layer in QD-LEDs.![]()
Collapse
Affiliation(s)
- Myeongjin Park
- Department of Electrical and Computer Engineering, Inter-university Semiconductor Research Center, Seoul National University Seoul 08826 Republic of Korea
| | - Jiyun Song
- Department of Electrical and Computer Engineering, Inter-university Semiconductor Research Center, Seoul National University Seoul 08826 Republic of Korea
| | - Myungchan An
- Realistic Media Research Center, Innovative Technology Research Division, Gumi Electronics & Information Technology Research Institute (GERI) Gumi 39253 Republic of Korea
| | - Jaehoon Lim
- Department of Energy Science, Center for Artificial Atoms, Sungkyunkwan University (SKKU) Suwon-Si Gyeonggi-do 16419 Republic of Korea
| | - Changhee Lee
- Department of Electrical and Computer Engineering, Inter-university Semiconductor Research Center, Seoul National University Seoul 08826 Republic of Korea
| | - Jeongkyun Roh
- Department of Electrical Engineering, Pusan National University Busan 46241 Republic of Korea
| | - Donggu Lee
- Realistic Media Research Center, Innovative Technology Research Division, Gumi Electronics & Information Technology Research Institute (GERI) Gumi 39253 Republic of Korea
| |
Collapse
|