Surface‐Modified Metallic Ti3C2Tx MXene as Electron Transport Layer for Planar Heterojunction Perovskite Solar Cells

• Published in: Advanced functional materials Vol. 29; no. 46
• Main Authors: Yang, Lin, Dall'Agnese, Chunxiang, Dall'Agnese, Yohan, Chen, Gang, Gao, Yu, Sanehira, Yoshitaka, Jena, Ajay Kumar, Wang, Xiao‐Feng, Gogotsi, Yury, Miyasaka, Tsutomu
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.11.2019
• Subjects: Electron mobility; Electron transfer; Electron transport; electron transport layers; Energy conversion efficiency; Energy storage; Heterojunctions; Materials science; MXenes; Optoelectronics; Ozone; perovskite solar cells; Perovskites; Photovoltaic cells; Solar cells; Ti3C2Tx MXene; Titanium; Two dimensional materials; UV‐ozone treatment
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201905694

MXenes are a large and rapidly expanding family of 2D materials that, owing to their unique optoelectronic properties and tunable surface termination, find a wide range of applications including energy storage and energy conversion. In this work, Ti3C2Tx MXene nanosheets are applied as a novel type of electron transport layer (ETL) in low‐temperature processed planar‐structured perovskite solar cells (PSCs). Interestingly, simple UV‐ozone treatment of the metallic Ti3C2Tx that increases the surface TiO bonds without any change in its bulk properties such as high electron mobility improves its suitability as an ETL. Improved electron transfer and suppressed recombination at the ETL/perovskite interface results in augmentation of the power conversion efficiency (PCE) from 5.00% in the case of Ti3C2Tx without UV‐ozone treatment to the champion PCE of 17.17%, achieved using the Ti3C2Tx film after 30 min of UV‐ozone treatment. As the first report on the use of pure MXene layer as an ETL in PSCs, this work shows the great potential of MXenes to be used in PSCs and displays their promise for applications in photovoltaic technology in general. UV‐ozone treatments for different times (0, 10, 30, and 60 min) are examined on the 2D metallic Ti3C2Tx films to take advantage of the tunable optoelectronic properties of MXenes as electron transport layers in low‐temperature processed planar‐structured perovskite solar cells, resulting in augmentation of the power conversion efficiency (PCE) from 5.00% to the champion PCE of 17.17%.