First principles insight into the structural, electronic, optical and thermodynamic properties of CsPb2Br5 compound

The ternary CsPb2Br5 compound is a promising candidate for optoelectronic applications, however, its electronic properties are not well understood yet. In this work, the structural, electronic, optical and thermodynamic properties have been systematically examined using first-principles calculations. The exchange-correlation po-tentials are included in the calculations through the generalized gradient approximation (GGA-PBESoI) and Tran-Blaha modified Becke-Johnson exchange (mBJ) potential. Obtained structural parameters match well with the experimental data. The CsPb2Br5 compound is an indirect semiconductor with a band gap of 3.589 eV predicted by mBJ potential. A wide absorption band in the ultraviolet region with very high absorption coef-ficient was observed for the ternary at hand. Finally, the thermodynamic behaviors of CsPb2Br5 are also com-puted using the Debye quasi-harmonic model. Properties are investigated as a function of pressure up to 25 GPa under different temperatures, and discussed in details.