Structural, Electronic and Optical Properties of Inorganic Perovskite CsPb(1-x)GexI3: A First Principle Approach

In recent years, the inorganic lead-based perovskites have significant consideration owing to their excellent structural stability. In this work, we explore the structural, electronic, and optical properties of α-CsPbI3 and Ge-incorporated α-CsPbI3 perovskites through first-principle calculations. The 12.5% of Ge-mixed CsPbI3 has pleasant structural stability compared to CsPbI3. The CsPb(1-x)GexI3 band gap is linearly decreased while increasing Ge concentration, and it varied from 1.45 to 1.12 eV. Besides, Ge doped CsPbI3 perovskites have a more substantial absorption coefficient in the visible regions. This result reveals, the Ge-incorporation on the B-site location enhanced structural stability and optical absorption coefficient of CsPbI3.