Improved Efficiency of Perovskite Light-Emitting Diodes Using a Three-Step Spin-Coated CH<sub>3</sub>NH<sub>3</sub>PbBr<sub>3</sub> Emitter and a PEDOT:PSS/MoO<sub>3</sub>-Ammonia Composite Hole Transport Layer
Yuanming Zhou,
Sijiong Mei,
Dongwei Sun,
Neng Liu,
Wuxing Shi,
Jiahuan Feng,
Fei Mei,
Jinxia Xu,
Yan Jiang,
Xianan Cao
Affiliations
Yuanming Zhou
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Sijiong Mei
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Dongwei Sun
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Neng Liu
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Wuxing Shi
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Jiahuan Feng
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Fei Mei
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Jinxia Xu
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Yan Jiang
Hubei Key Laboratory for High-efficiency Use of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, China
Xianan Cao
Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA
High efficiency perovskite light-emitting diodes (PeLEDs) using PEDOT:PSS/MoO3-ammonia composite hole transport layers (HTLs) with different MoO3-ammonia ratios were prepared and characterized. For PeLEDs with one-step spin-coated CH3NH3PbBr3 emitter, an optimal MoO3-ammonia volume ratio (0.02) in PEDOT:PSS/MoO3-ammonia composite HTL presented a maximum luminance of 1082 cd/m2 and maximum current efficiency of 0.7 cd/A, which are 82% and 94% higher than those of the control device using pure PEDOT:PSS HTL respectively. It can be explained by that the optimized amount of MoO3-ammonia in the composite HTLs cannot only facilitate hole injection into CH3NH3PbBr3 through reducing the contact barrier, but also suppress the exciton quenching at the HTL/CH3NH3PbBr3 interface. Three-step spin coating method was further used to obtain uniform and dense CH3NH3PbBr3 films, which lead to a maximum luminance of 5044 cd/m2 and maximum current efficiency of 3.12 cd/A, showing enhancement of 750% and 767% compared with the control device respectively. The significantly improved efficiency of PeLEDs using three-step spin-coated CH3NH3PbBr3 film and an optimum PEDOT:PSS/MoO3-ammonia composite HTL can be explained by the enhanced carrier recombination through better hole injection and film morphology optimization, as well as the reduced exciton quenching at HTL/CH3NH3PbBr3 interface. These results present a promising strategy for the device engineering of high efficiency PeLEDs.
