Achieving Small Temperature Coefficients in Carbon‐Based Perovskite Solar Cells by Enhancing Electron Extraction. Issue 23 (14th September 2022)

• Record Type: Journal Article
• Authors: Zhang, Xian; Guan, Yan; Zhang, Yangyang; Yu, Wenjin; Wu, Cuncun; Han, Jiaheng; Zhang, Yafei; Chen, Cong; Zheng, Shijian; Xiao, Lixin
• Is Part Of: Advanced optical materials. Volume 10:Issue 23(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-14
• Subjects: brookite TiO 2 nanoneedles -- carbon electrode -- FAPbI 3 -- PCBM coating -- perovskite solar cells -- temperature coefficients; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202201598
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Hole transport layer (HTL)‐free carbon electrode‐based perovskite solar cells (C‐PSCs) have drawn great attention due to their excellent stability and simple fabrication process. However, the photovoltaic parameters of C‐PSCs usually exhibit large negative temperature coefficients (TCs). Herein, the TCs of C‐PSCs can be suppressed by enhancing electron extraction. An efficient electron transport layer (ETL), [6, 6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)‐coated nanoneedle‐like brookite TiO2 (ND‐B‐TiO2 ) is used as ETL to prepare HTL‐free pure FAPbI3 ‐based C‐PSCs. Compared with bare ND‐B‐TiO2, PCBM@ND‐B‐TiO2 shows higher electron mobility, and better band alignment with formamidinium lead triiodide (FAPbI3 ) perovskite, as well as improved contact with perovskite, which leads to enhanced electron extraction and transportation. Consequently, the power conversion efficiency (PCE) of HTL‐free carbon‐based FAPbI3 PSC can reach up to 14.55%, which is one of the highest efficiencies for FAPbI3 ‐based planar C‐PSCs so far. More importantly, the optimized device is less sensitive to the operating temperature due to the boosted carrier extraction and passivated interface defects, showing a small TC(PCE) of only ≈−0.11%/°C between 25 °C and 85 °C. The work demonstrates that enhancing electron extraction is an effective way to achieve high‐performance C‐PSCs and high‐temperature solar cells. Abstract : The authors introduce a method to suppress the temperature coefficient of carbon electrode‐based perovskite solar cell (C‐PSC) by enhanced electron extraction. An efficient electron transport layer (ETL), PCBM‐coated nanoneedle‐like brookite TiO2 is used as ETL to prepare HTL‐free pure FAPbI3 ‐based C‐PSCs. The device has a high efficiency of 14.55% and a small temperature coefficient of −0.11%/°C between 25 °C and 85 °C.