Chemically Stable Black Phase CsPbI3 Inorganic Perovskites for High‐Efficiency Photovoltaics

• Published in: Advanced materials (Weinheim) 2020-11, Vol.32 (45), p.e2001025-n/a
• Main Authors: Wang, Yong, Chen, Yuetian, Zhang, Taiyang, Wang, Xingtao, Zhao, Yixin
• Format: Article
• Language: English
• Subjects: Cations; Cesium; Crystal structure; CsPbI 3; Efficiency; Hydrogen bonds; inorganic perovskite; Materials science; Optoelectronics; perovskite solar cell; Perovskites; Phase stability; Photovoltaic cells; Physical properties; Room temperature; Solar cells; stability
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202001025

Research on chemically stable inorganic perovskites has achieved rapid progress in terms of high efficiency exceeding 19% and high thermal stabilities, making it one of the most promising candidates for thermodynamically stable and high‐efficiency perovskite solar cells. Among those inorganic perovskites, CsPbI3 with good chemical components stability possesses the suitable bandgap (≈1.7 eV) for single‐junction and tandem solar cells. Comparing to the anisotropic organic cations, the isotropic cesium cation without hydrogen bond and cation orientation renders CsPbI3 exhibit unique optoelectronic properties. However, the unideal tolerance factor of CsPbI3 induces the challenges of different crystal phase competition and room temperature phase stability. Herein, the latest important developments regarding understanding of the crystal structure and phase of CsPbI3 perovskite are presented. The development of various solution chemistry approaches for depositing high‐quality phase‐pure CsPbI3 perovskite is summarized. Furthermore, some important phase stabilization strategies for black phase CsPbI3 are discussed. The latest experimental and theoretical studies on the fundamental physical properties of photoactive phase CsPbI3 have deepened the understanding of inorganic perovskites. The future development and research directions toward achieving highly stable CsPbI3 materials will further advance inorganic perovskite for highly stable and efficient photovoltaics. The recent progress of CsPbI3 perovskite for highly efficient and stable photovoltaics is summarized. Furthermore, those important phase stabilization strategies for black‐phase CsPbI3 are also discussed. With the advancing of fundamental studies on CsPbI3 perovskite material properties, the CsPbI3 perovskite and other inorganic perovskites will become more and more promising for high‐efficiency and stable perovskite solar cells.