Bottom Contact Engineering for Ambient Fabrication of >25% Durable Perovskite Solar Cells

Ligang Yuan(State Key Laboratory of Luminescent Materials and Devices), Shibing Zou(State Key Laboratory of Luminescent Materials and Devices), Kaicheng Zhang(Friedrich-Alexander-Universität Erlangen-Nürnberg), Peng Huang(Southwest Jiaotong University), Yuyan Dong(State Key Laboratory of Luminescent Materials and Devices), Jiarong Wang(State Key Laboratory of Luminescent Materials and Devices), Kezhou Fan(Hong Kong University of Science and Technology), Man Yu Lam(Hong Kong University of Science and Technology), Xiaoshuai Wu(Chinese University of Hong Kong), Wei Cheng(Southwest Jiaotong University), Ruijia Tang(Beijing University of Chemical Technology), Wenhao Chen(Nanchang Hangkong University), Weiqing Liu(Nanchang Hangkong University), Kam Sing Wong(Hong Kong University of Science and Technology), Keyou Yan(State Key Laboratory of Luminescent Materials and Devices)
Advanced Materials
August 2, 2024
Cited by 53Open Access
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Abstract

Abstract The bottom contact in perovskite solar cells (PSCs) is easy to cause deep trap states and severe instability issues, especially under maximum power point tracking (MPPT). In this study, sodium gluconate (SG) is employed to disperse tin oxide (SnO 2 ) nanoparticles (NPs) and regulate the interface contact at the buried interface. The SG‐SnO 2 electron transfer layer (ETL) enabled the deposition of pinhole‐free perovskite films in ambient air and improved interface contact by bridging effect. SG‐SnO 2 PSCs achieved an impressive power conversion efficiency (PCE) of 25.34% (certified as 25.17%) with a high open‐circuit voltage ( V OC ) exceeding 1.19 V. The V OC loss is less than 0.34 V relative to the 1.53 eV bandgap, and the fill factor (FF) loss is only 2.02% due to the improved contact. The SG‐SnO 2 PSCs retained around 90% of their initial PCEs after 1000 h operation (T 90 = 1000 h), higher than T 80 = 1000 h for the control SnO 2 PSC. Microstructure analysis revealed that light‐induced degradation primarily occurred at the buried holes and grain boundaries and highlighted the importance of bottom‐contact engineering.


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