Feng Wenhuai, Liu Xudong, Liu Gengling, Yang Guo, Fang Yuxuan, Shen Jinliang, Jin Bowen, Chen Xi, Huang Yu-Hua, Wang Xu-Dong, Wu Congcong, Yang Shaopeng, Wu Wu-Qiang
Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, LIFM, School of Chemistry, IGCME, Sun Yat-Sen University, Guangzhou, 510275, China.
Province-Ministry Co-construction Collaborative Innovation Center of Hebei Photovoltaic Technology, College of Physics Science and Technology, Hebei University, Baoding, 071002, China.
Angew Chem Int Ed Engl. 2024 Sep 23;63(39):e202403196. doi: 10.1002/anie.202403196. Epub 2024 Aug 21.
Photoactive black-phase formamidinium lead triiodide (α-FAPbI) perovskite has dominated the prevailing high-performance perovskite solar cells (PSCs), normally for those spin-coated, conventional n-i-p structured devices. Unfortunately, α-FAPbI has not been made full use of its advantages in inverted p-i-n structured PSCs fabricated via blade-coating techniques owing to uncontrollable crystallization kinetics and complicated phase evolution of FAPbI perovskites during film formation. Herein, a customized crystal surface energy regulation strategy has been innovatively developed by incorporating 0.5 mol % of N-aminoethylpiperazine hydroiodide (NAPI) additive into α-FAPbI crystal-derived perovskite ink, which enabled the formation of highly-oriented α-FAPbI films. We deciphered the phase transformation mechanisms and crystallization kinetics of blade-coated α-FAPbI perovskite films via combining a series of in-situ characterizations and theoretical calculations. Interestingly, the strong chemical interactions between the NAPI and inorganic Pb-I framework help to reduce the surface energy of (100) crystal plane by 42 %, retard the crystallization rate and lower the formation energy of α-FAPbI. Benefited from multifaceted advantages of promoted charge extraction and suppressed non-radiative recombination, the resultant blade-coated inverted PSCs based on (100)-oriented α-FAPbI perovskite films realized promising efficiencies up to 24.16 % (~26.5 % higher than that of the randomly-oriented counterparts), accompanied by improved operational stability. This result represented one of the best performances reported to date for FAPbI-based inverted PSCs fabricated via scalable deposition methods.
光活性黑相甲脒铅三碘化物（α-FAPbI）钙钛矿一直主导着主流的高性能钙钛矿太阳能电池（PSC），通常用于那些旋涂的传统n-i-p结构器件。不幸的是，由于在成膜过程中FAPbI钙钛矿的结晶动力学不可控以及相演变复杂，α-FAPbI在通过刮刀涂布技术制备的倒置p-i-n结构PSC中尚未充分发挥其优势。在此，通过将0.5 mol%的氢碘酸N-氨乙基哌嗪（NAPI）添加剂掺入α-FAPbI晶体衍生的钙钛矿油墨中，创新性地开发了一种定制的晶体表面能调控策略，从而能够形成高度取向的α-FAPbI薄膜。我们通过结合一系列原位表征和理论计算，解读了刮刀涂布的α-FAPbI钙钛矿薄膜的相变机制和结晶动力学。有趣的是，NAPI与无机Pb-I骨架之间的强化学相互作用有助于将（100）晶面的表面能降低42%，延缓结晶速率并降低α-FAPbI的形成能。受益于电荷提取增强和非辐射复合抑制的多方面优势，基于（100）取向α-FAPbI钙钛矿薄膜的所得刮刀涂布倒置PSC实现了高达24.16%的有前景的效率（比随机取向的对应物高约26.5%），同时提高了操作稳定性。该结果代表了通过可扩展沉积方法制备的基于FAPbI的倒置PSC迄今为止报道的最佳性能之一。
