Band-Gap Narrowing and Electric Transport Regulation of Hybrid Perovskites via Pressure Engineering

作者：Yue Wang, Xuening Sun, Tianyin Shao, Dianlong Zhao, Long Zhang, Yongguang Li, Qingfeng Dong, Cailong Liu, Kai Wang, Guanjun Xiao, Bo Zou · 发表于：Inorganic Chemistry · 年份：2024 · DOI：10.1021/acs.inorgchem.4c01555 · 被引用次数：12 · 研究领域：Perovskite Materials and Applications、Electronic and Structural Properties of Oxides、Magnetic and transport properties of perovskites and related materials

Lead-free organic–inorganic hybrid perovskites are one class of promising optoelectronic materials that have attracted much attention due to their outstanding stability and environmentally friendly nature. However, the intrinsic band gap far from the Shockley–Queisser limit and the inferior electrical properties largely limit their applicability. Here, a considerable band-gap narrowing from 2.43 to 1.64 eV with the compression rate up to 32.5% is achieved via high-pressure engineering in the lead-free hybrid perovskite MA 3 Sb 2 I 9 . Meanwhile, the electric transport process changes from the initial interaction of both ions and electrons to only the contribution of electrons upon compression. The alteration in electrical characteristics is ascribed to the vibration limitation of organic ions and the enhanced orbital overlap, resulting from the reduction of the Sb–I bond length through pressure-induced phase transitions. This work not only systematically investigates the correlation between the structural and optoelectronic properties of MA 3 Sb 2 I 9 but also provides a potential pathway for optimizing electrical properties in lead-free hybrid perovskites.