Li Zhiqi, Xie Xiyun, Ai Zhenhai, Han Yu, Zhu Tao, Ma Ruijie, Liu Heng, Lu Xinhui, Wei Qi, Li Mingjie, Xiao Junyan, Liu Kuan, Ren Zhiwei, Li Gang
Department of Electrical and Electronic Engineering, Photonic Research Institute (PRI), Research Institute of Smart Energy (RISE), The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 999077, China.
Department of Physics, Chinese University of Hong Kong, New Territories, Hong Kong, 999077, China.
Adv Mater. 2025 Jul;37(26):e2502436. doi: 10.1002/adma.202502436. Epub 2025 Apr 16.
Carbon-based CsPbIBr perovskite solar cells (PSCs) free of a hole-transport layer (HTL) have emerged as promising photovoltaics due to their low processing cost and superior stability. However, the voltage deficit resulting from inefficient carrier extraction causes insufficient power conversion efficiency (PCE), severely hindering their progress. Here, a gradient electron energy level modulation strategy proves effective in reducing voltage losses through the rapid extraction of photogenerated electrons. This process enhances carrier separation/collection and reduces recombination at the back contact, thereby achieving high-performance photovoltaics. It is demonstrated that the front electron extraction, equally critical as the prevailing back perovskite/carbon contact, accounts for the significant contributing factor of voltage deficit in carbon-based HTL-free PSCs. The resulting PSCs deliver a record open-circuit voltage (V) of 1.41 V and a PCE of 17.42% and retain more than 92% of their initial efficiency after 1, 000 h. These results highlight the significant potential of carbon-based HTL-free perovskite photovoltaics.
不含空穴传输层（HTL）的碳基CsPbIBr钙钛矿太阳能电池（PSC）因其低加工成本和卓越稳定性，已成为颇具前景的光伏器件。然而，载流子提取效率低下导致的电压损失致使功率转换效率（PCE）不足，严重阻碍了其发展进程。在此，一种梯度电子能级调制策略被证明可通过快速提取光生电子有效降低电压损失。这一过程增强了载流子的分离/收集，并减少了背接触处的复合，从而实现了高性能光伏器件。结果表明，与普遍存在的钙钛矿/碳背接触同样关键的前表面电子提取，是碳基无HTL PSC中电压损失的重要影响因素。由此制备的PSC实现了创纪录的1.41 V开路电压（V）和17.42%的PCE，并且在1000小时后仍保留其初始效率的92%以上。这些结果凸显了碳基无HTL钙钛矿光伏器件的巨大潜力。
