Articles by Tai Cheng in JoVE
Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode Zhibin Wang1, Tai Cheng1, Fuzhi Wang1, Yiming Bai1, Xingming Bian1, Bing Zhang1, Tasawar Hayat2,3, Ahmed Alsaedi3, Zhan'ao Tan1 1State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, 2Department of Mathematics, Quaid-I-Azam University, 3NAAM Research Group, Faculty of Science, King Abdulaziz University A protocol is presented for fabricating high-performance, pure blue ZnCdS/ZnS-based quantum dots light-emitting diodes by employing an autoxidized aluminum cathode.
Other articles by Tai Cheng on PubMed
Morphology Engineering for High-Performance and Multicolored Perovskite Light-Emitting Diodes with Simple Device Structures Small (Weinheim an Der Bergstrasse, Germany). Aug, 2016 | Pubmed ID: 27392198 The film morphology is extremely significant for solution processed perovskite devices. Through fine morphology engineering without using any additives or further posttreatments, a full-coverage and high quantum yield perovskite film has been achieved based on one-step spin-coating method. The morphologies and film characteristics of MAPbBr3 with different MABr:PbBr2 starting material ratios are in-depth investigated by scanning electron microscopy, atomic force microscopy, X-ray diffraction, photoluminescence, and time resolved photoluminescence. High performance organometal halide perovskite light-emitting didoes (PeLEDs) based on simple device structure of indium tin oxide/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (
Tetraphenylmethane-Arylamine Hole-Transporting Materials for Perovskite Solar Cells ChemSusChem. 03, 2017 | Pubmed ID: 27976519 A new class of hole-transporting materials (HTM) containing tetraphenylmethane (TPM) core have been developed. After thermal, charge carrier mobility, and contact angle tests, it was found that TPA-TPM (TPA: arylamine derivates side group) showed higher glass-transition temperature and larger water-contact angle than spiro-OMeTAD with comparable hole mobility. Photoluminescence and impedance spectroscopy studies indicate that TPA-TPM's hole-extraction ability is comparable to that of spiro-OMeTAD. SEM and AFM results suggest that TPA-TPM has a smooth surface. When TPA-TPM is used in mesoscopic perovskite solar cells, power conversion efficiency comparable to that of spiro-OMeTAD is achieved. Notably, the perovskite solar cells employing TPA-TPM show better long-term stability than that of spiro-OMeTAD. Moreover, TPA-TPM can be prepared from relatively inexpensive raw materials with a facile synthetic route. The results demonstrate that TPM-arylamines are a new class of HTMs for efficient and stable perovskite solar cells.
Optical-Electrical-Chemical Engineering of PEDOT:PSS by Incorporation of Hydrophobic Nafion for Efficient and Stable Perovskite Solar Cells ACS Applied Materials & Interfaces. Jan, 2018 | Pubmed ID: 29308652 In PIN-type perovskite solar cells (PSCs), the hydroscopicity and acidity of the poly(3,4-ethylenedioxythiophene)-poly(styrene-sulfonate) (PEDOT:PSS) hole transport layer (HTL) have critical influences on the device stability. To eliminate these problems, Nafion, the hydrophobic perfluorosulfonic copolymer, is incorporated into PEDOT:PSS by a simple spin-coating process. For the modified film, Nafion/PSSH (poly(styrene sulfonate) acid) acts as an electron-blocking layer on the surface and the PEDOT-rich domain tends to gather into larger particles with better interchain charge transfer inside the film. Consequently, the modified PEDOT:PSS HTL shows enhanced conductivity and light transmittance as well as more favorable work function, ending up with the increased short-circuit current density (J) and open-circuit voltage (V) of the device. Finally, PSCs with Nafion-modified HTLs achieve the best power conversion efficiency of 16.72%, with 23.76% improvement compared with PEDOT:PSS-only devices (13.51%). Most importantly, the device stability is obviously enhanced because of the hydrophobicity and chemical and mechanical stability of the Nafion polymer that is enriched on the surface of the PEDOT:PSS film.