CsPbI3 exhibits multiple crystal phases, and the kinetic barriers for phase transitions are relatively low, facilitating the formation of abundant interphase boundaries (IBs) during phase transitions. These IB structures significantly influence the optoelectronic performance of the material. In this work, based on three types of CsPbI3 IB structures, we systematically investigate the effects of pressure on the formation feasibility and optoelectronic properties of these IBs by calculating their formation energies, band alignments, optical absorption characteristics, and carrier effective masses. The results show that moderate pressure can increase the formation feasibility of certain IB structures and effectively modulate the band alignment at the CsPbI3 IBs, thereby enabling the switching of different optoelectronic functions within the same material. Meanwhile, the application of pressure can also improve optical absorption and the spectroscopic-limited maximum efficiency, and reduce carrier effective masses in some IB systems, which is beneficial for enhancing carrier transport capabilities. This study demonstrates that pressure serves as an effective means to regulate the IB structures and optoelectronic properties of CsPbI3, providing theoretical support for the design of multifunctional optoelectronic materials based on IB engineering and for expanding photovoltaic applications.
Shi et al. (Sat,) studied this question.