Wang Chaoyang, Xiang Junwei, Liu Jiale, Han Chuanzhou, Zheng Ziwei, Xia Minghao, Shen Song, Cui Zhaozhen, Wang Xiaoru, Xie Jiayu, Li Xiaoyu, Mei Anyi, Zhou Yang, Han Hongwei
Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei, 430074, P. R. China.
Adv Mater. 2025 Jul;37(27):e2502724. doi: 10.1002/adma.202502724. Epub 2025 May 7.
Carbon-based hole transport layer-free (C-HTL-free) perovskite solar cells (PSCs) are promising for low-cost and stable photovoltaics, but the HTL absence deteriorates their power conversion efficiency (PCE) due to the lack of back surface field (BSF). In this work, the benefits of forming dual BSFs in improving the PCE of C-HTL-free PSCs are first investigated by simulation. Then, trityl tetrakis(pentafluorophenyl)borate (TrTPFB) is introduced into the C-HTL-free PSCs by post-treatment for the first time, which enables the formation of dual BSFs. TPFB passivates n-doping defects in perovskite and leads to the formation of perovskite n-p homojunction, while Tr extracts electrons from carbon and lowers its work function, which succeeds realizing dual BSFs. This improves the separation and extraction of photocarriers within the device, which is evidenced by the photoluminescence lifetime imaging of the device cross-section for the first time. As a result, the average open-circuit voltage increases significantly by about 70 mV, which largely contributes to the improvement of PCE with a champion value of 20.79% obtained.
无碳基空穴传输层（C-HTL-free）的钙钛矿太阳能电池（PSC）对于低成本且稳定的光伏发电具有潜力，但由于缺乏背表面场（BSF），缺少HTL会降低其功率转换效率（PCE）。在这项工作中，首先通过模拟研究了形成双背表面场对提高无C-HTL的PSC的PCE的益处。然后，首次通过后处理将三芳基四（五氟苯基）硼酸盐（TrTPFB）引入无C-HTL的PSC中，这使得能够形成双背表面场。TPFB钝化钙钛矿中的n型掺杂缺陷并导致钙钛矿n-p同质结的形成，而Tr从碳中提取电子并降低其功函数，成功实现了双背表面场。这改善了器件内光载流子的分离和提取，首次通过器件横截面的光致发光寿命成像得到了证明。结果，平均开路电压显著增加约70 mV，这在很大程度上有助于提高PCE，获得的最佳值为20.79%。
