First-principles study of the structural, mechanical, electronic, optical, and elastic properties of non-toxic XGeBr3 (X=K, Rb, and Cs) perovskite for optoelectronic and radiation sensing applications

Band gap tuning of perovskite solar cells for enhancing the efficiency and stability: issues and prospects

“…It is known that A-site atoms have less impact on the frontier band structure of the materials than Bsite and X-site atoms. [90][91][92] However, sometimes replacing A-site components can contribute to enhancing the stability of the structure. It has been reported that substituting the A-site with formamidinium (FA) leads to a lower band-gap and improved stability.…”