Marked Efficiency Improvement of FAPb0.7Sn0.3Br3 Perovskite Light-Emitting Diodes by Optimization of the Light-Emitting Layer and Hole-Transport Layer

Lufeng Hu; Zhixiang Ye; Dan Wu; Zhaojin Wang; Weigao Wang; Kai Wang; Xiangqian Cui; Ning Wang; Hongyu An; Bobo Li; Bingxi Xiang; Mingxia Qiu

doi:10.3390/nano12091454

Marked Efficiency Improvement of FAPb_0.7Sn_0.3Br₃ Perovskite Light-Emitting Diodes by Optimization of the Light-Emitting Layer and Hole-Transport Layer

Nanomaterials (Basel). 2022 Apr 25;12(9):1454. doi: 10.3390/nano12091454.

Authors

Lufeng Hu¹, Zhixiang Ye¹, Dan Wu¹, Zhaojin Wang², Weigao Wang³, Kai Wang², Xiangqian Cui¹, Ning Wang¹, Hongyu An¹, Bobo Li¹, Bingxi Xiang¹, Mingxia Qiu¹

Affiliations

¹ College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, China.
² Guangdong University Key Lab for Advanced Quantum Dot Displays and Lighting, Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting, and Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
³ Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.

Abstract

Highly luminescent FAPb_0.7Sn_0.3Br₃ nanocrystals with an average photoluminescence (PL) quantum yield of 92% were synthesized by the ligand-assisted reprecipitation method. The 41-nm-thick perovskite film with a smooth surface and strong PL intensity was proven to be a suitable luminescent layer for perovskite light-emitting diodes (PeLEDs). Electrical tests indicate that the double hole-transport layers (HTLs) played an important role in improving the electrical-to-optical conversion efficiency of PeLEDs due to their cascade-like level alignment. The PeLED based on poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,40-(N-(p-butylphenyl))-diphenylamine)] (TFB)/poly(9-vinylcarbazole) (PVK) double HTLs produced a high external quantum efficiency (EQE) of 9%, which was improved by approximately 10.9 and 5.14 times when compared with single HTL PVK or the TFB device, respectively. The enhancement of the hole transmission capacity by TFB/PVK double HTLs was confirmed by the hole-only device and was responsible for the dramatic EQE improvement.

Keywords: FAPb0.7Sn0.3Br3 film; double hole transport structure; light-emitting layer thickness; perovskite light-emitting diode.

Abstract

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