Nano-Micro Letters, Volume. 16, Issue 1, 191(2024)

TiO2 Electron Transport Layer with p–n Homojunctions for Efficient and Stable Perovskite Solar Cells

Wenhao Zhao1... Pengfei Guo1,4,*, Jiahao Wu1, Deyou Lin1, Ning Jia1, Zhiyu Fang1, Chong Liu1, Qian Ye1, Jijun Zou3, Yuanyuan Zhou2, and Hongqiang Wang14,** |Show fewer author(s)
Author Affiliations
  • 1State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi’an 710072, People’s Republic of China
  • 2Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Clear Water Bay Hong Kong SAR, People’s Republic of China
  • 3Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People’s Republic of China
  • 4Chongqing Innovation Center of Northwestern, Polytechnical University, Northwestern Polytechnical University, Chongqing 401135, People’s Republic of China
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    Low-temperature processed electron transport layer (ETL) of TiO2 that is widely used in planar perovskite solar cells (PSCs) has inherent low carrier mobility, resulting in insufficient photogenerated electron transport and thus recombination loss at buried interface. Herein, we demonstrate an effective strategy of laser embedding of p-n homojunctions in the TiO2 ETL to accelerate electron transport in PSCs, through localized build-in electric fields that enables boosted electron mobility by two orders of magnitude. Such embedding is found significantly helpful for not only the enhanced crystallization quality of TiO2 ETL, but the fabrication of perovskite films with larger-grain and the less-trap-states. The embedded p–n homojunction enables also the modulation of interfacial energy level between perovskite layers and ETLs, favoring for the reduced voltage deficit of PSCs. Benefiting from these merits, the formamidinium lead iodide (FAPbI3) PSCs employing such ETLs deliver a champion efficiency of 25.50%, along with much-improved device stability under harsh conditions, i.e., maintain over 95% of their initial efficiency after operation at maximum power point under continuous heat and illumination for 500 h, as well as mixed-cation PSCs with a champion efficiency of 22.02% and over 3000 h of ambient storage under humidity stability of 40%. Present study offers new possibilities of regulating charge transport layers via p-n homojunction embedding for high performance optoelectronics.

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    Wenhao Zhao, Pengfei Guo, Jiahao Wu, Deyou Lin, Ning Jia, Zhiyu Fang, Chong Liu, Qian Ye, Jijun Zou, Yuanyuan Zhou, Hongqiang Wang. TiO2 Electron Transport Layer with p–n Homojunctions for Efficient and Stable Perovskite Solar Cells[J]. Nano-Micro Letters, 2024, 16(1): 191

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    Paper Information

    Category: Research Articles

    Received: Jan. 22, 2024

    Accepted: Mar. 20, 2024

    Published Online: Jan. 23, 2025

    The Author Email: Guo Pengfei (guopengfei@nwpu.edu.cn), Wang Hongqiang (hongqiang.wang@nwpu.edu.cn)

    DOI:10.1007/s40820-024-01407-3

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