Machine learning, theoretical exploration and device simulation of Cs2NaXCl6 (X = Bi, In, Sb, Sc) double halide perovskites with spatial applications

Abstract

With the growing interest in cosmic spatial, perovskite solar cells are not only for terrestrial applications, but are also attractive as a space technology. However, the extraterrestrial environment requires certain properties of the materials. In this paper, we screened suitable double perovskite models by machine modeling and used first-principles calculations to analyze the structural, mechanical, optical, and electronic properties. Geometrical parameters demonstrate that Cs₂NaBiCl₆, Cs₂NaInCl₆, Cs₂NaSbCl₆ and Cs₂NaScCl₆ all have stable structures, and molecular dynamics simulation characterizes the thermodynamic stability. Mechanical results show that Cs₂NaBiCl₆, Cs₂NaInCl₆, Cs₂NaSbCl₆ and Cs₂NaScCl₆ have bulk modulus higher than 16 GPa, which is resistant to deformation. Optical property calculations display good absorption in the spatial UV band range. Electronic properties explore the elemental orbital contributions leading to the band gaps. Simulations of solar cells in the AM0 environment show that the conversion efficiency is not low in the space environment and improves with increasing Jsc, making it promising for space applications. The superior flexibility of dual perovskites has potential as a device in space environments, and promotes the development of functional devices, especially for applications that require high stability.