近日，香港大学的Wallace C. H. Choy及其研究小组与南方科技大学的徐保民等人合作并取得一项新进展。经过不懈努力，他们发现共晶分子配体能够稳定光活性黑相钙钛矿。相关研究成果已于2025年1月8日在国际知名学术期刊《自然—光子学》上发表。
该研究团队报道了一种利用氢键共晶分子（EM）作为[PbI6]4-八面体配体的方法，以促进角共享八面体的主导形成。研究结果表明，通过提高角共享八面体与面共享八面体的比例，可以促使完全的相变，并有利于形成纯立方结构的钙钛矿。基于EM制备的薄膜的钙钛矿太阳能电池提供了25.8%的功率转换效率（经认证为25.7%），并且具有优异的稳定性，T95寿命约为2000小时。
据悉，富甲脒的三碘化物钙钛矿作为下一代光伏技术的吸光层展现出巨大潜力。然而，该钙钛矿在结晶过程中会经历复杂的相变，通常会产生不理想的六方相，从而导致太阳能电池效率和稳定性的下降。
附：英文原文
Title: Eutectic molecule ligand stabilizes photoactive black phase perovskite
Author: Gao, Zhi-Wen, Wang, Deng, Fang, Jun, Zheng, Guanhaojie, Sun, Jiayun, Tao, Yiran, Zeng, Jie, Qiu, Longbin, Lu, Xinhui, Su, Haibin, Wang, Yong, Xu, Baomin, Choy, Wallace C. H.
Issue&Volume: 2025-01-08
Abstract: Formamidinium-rich triiodide perovskites show great promise as light-absorption layers for next photovoltaic technology. However, the intricate process of phase transformation during the crystallization of this perovskite typically results in the presence of undesired hexagonal phases, leading to a degradation in solar cell efficiency and stability. Here we report the use of a hydrogen-bonded eutectic molecule (EM) as a [PbI6]4- octahedra ligand to promote the dominant formation of corner-sharing octahedra. Our results demonstrate that the increased ratio of corner-sharing octahedra to face-sharing octahedra can prompt a complete phase transformation and facilitate the formation of pure cubic structure perovskite. Perovskite solar cells based on EM-fabricated films provide a power conversion efficiency of 25.8% (certified 25.7%) and excellent stability with a T95 lifetime of ~2,000h.
DOI: 10.1038/s41566-024-01596-8
Source: https://www.nature.com/articles/s41566-024-01596-8