Examining the uniform strain effect on elastic, electronic and optical properties of CsPbCl3 through FP-LAPW calculations

We study comprehensively the uniform strain effect on the elastic, electronic and optical properties of the perovskite CsPbCl3 using theoretical calculations based on the Full-Potential Linearized Augmented Plane-Wave (FP-LAPW) method. The Generalized Gradient Approximation (GGA-PBESol) and Tran-Blaha modified Becke-Johnson exchange potential improved by Koller (KmBJ) are adopted to describe the electron exchange-correlation interactions. The compound is elastically stable and ductile. And its mechanical resistance increases with the compressive strain but decreases with the tensile stress. Based on results, CsPbCl3 is a direct semiconductor with band gap of 2.990 eV, which increases when the strain switches nature from compressive to tensile. The optical absorption of CsPbCl3 can be enhanced by applying a compressive strain, and the absorption band can be widen to 620 nm in the visible region with a compressive strain of -5%, making it suitable for photovoltaic applications. Therefore, the strain engineering on CsPbCl3 may be very useful to determine suitable parameters for applications in the optoelectronics industry.