Photo-stable perovskite solar cells with reduced interfacial recombination losses using a CeOx interlayer

• Published in: Science China materials Vol. 64; no. 8; pp. 1858 - 1867
• Main Authors: Shi, Xiaoqiang, Tao, Ye, Li, Zhuoxin, Peng, Huirong, Cai, Molang, Liu, Xuepeng, Zhang, Zhongyan, Dai, Songyuan
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.08.2021; Springer Nature B.V
• Subjects: Charge transport; Chemistry and Materials Science; Chemistry/Food Science; Electron transport; Energy conversion efficiency; Interlayers; Low temperature; Materials Science; Open circuit voltage; Perovskites; Photovoltaic cells; Solar cells; Titanium dioxide; Transport properties; interface passivation; perovskite solar cell; recombination; CeO; light stability
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-020-1625-2

Despite demonstrating remarkable power conversion efficiencies (PCEs), perovskite solar cells (PSCs) have not yet achieved their full potential. In particular, the interfaces between the perovskite and charge transport layers account for the vast majority of the recombination losses. Interfacial contact and band alignment between the low-temperature-processed TiO 2 electron transport layer (ETL) and the perovskite are essential to minimize nonradiative recombination losses. In this study, a CeO x interlayer is employed to modify the perovskite/TiO 2 interface, and the charge transport properties of the devices are investigated. The bilayer-structured TiO 2 /CeO x ETL leads to the modification of the interface energetics, resulting in improved electron extraction and reduced nonradiative recombination in the PSCs. Devices based on TiO 2 /CeO x ETL exhibit a high open-circuit voltage ( V oc ) of 1.13 V and an enhanced PCE of more than 20% as compared with V oc of 1.08 V and a PCE of approximately 18% for TiO 2 -based devices. Moreover, PSCs based on TiO 2 /CeO x ETL maintain over 88% of their initial PCEs after light illumination for 300 min, whereas PSCs based on TiO 2 ETL almost failed. This study provides an efficient strategy to enhance the PCE and stability of PSCs based on a low-temperature-processed TiO 2 ETL.