Low-cost solution-processed copper iodide as an alternative to PEDOT:PSS hole transport layer for efficient and stable inverted planar heterojunction perovskite solar cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 3; no. 38; pp. 19353 - 19359
• Main Authors: Chen, Wei-Yi, Deng, Lin-Long, Dai, Si-Min, Wang, Xin, Tian, Cheng-Bo, Zhan, Xin-Xing, Xie, Su-Yuan, Huang, Rong-Bin, Zheng, Lan-Sun
• Format: Journal Article
• Language: English
• Published: 01.01.2015
• Subjects: COPPER IODIDE; COSTS; Devices; ELECTRONIC PRODUCTS; Heterojunctions; HOLES; INTERFACES; Iodides; Perovskites; Photovoltaic cells; Solar cells; Stability; Transport
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c5ta05286f

Inverted planar heterojunction (PHJ) perovskite solar cells have attracted great attention due to their advantage of low-temperature fabrication on flexible substrates by solution processing with high efficiency. Poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) is the most widely used hole transport layer (HTL) in inverted PHJ perovskite solar cells; however, the acidic and hygroscopic nature of PEDOT:PSS can cause degradation and reduce the device stability. In this work, we demonstrated that low-cost solution-processed hydrophobic copper iodide (CuI) can serve as a HTL to replace PEDOT:PSS in inverted PHJ perovskite solar cells with high performance and enhanced device stability. A power conversion efficiency (PCE) of 13.58% was achieved by employing CuI as the HTL, slightly exceeding the PEDOT:PSS based device with a PCE of 13.28% under the same experimental conditions. Furthermore, the CuI based devices exhibited better air stability than PEDOT:PSS based devices. The results indicate that low-cost solution-processed CuI is a promising alternative to the PEDOT:PSS HTL and could be widely used in inverted PHJ perovskite solar cells.