Sn(IV) Inserted Lead‐Free Perovskite Materials (MA3(Bi1−xSnx)2I9) as Light Absorbers: Bandgap Engineering and Enhanced Photovoltaic Performance

Recently, methyl ammonium bismuth iodide (MA 3 Bi 2 I 9 ) and methyl ammonium antimony iodide (MA 3 Sb 2 I 9 ) perovskite structures have received enormous attention because of their good aerobic stability. In particular, MA 3 Bi 2 I 9 perovskite‐like material is widely explored as a visible light absorber in the construction of lead‐free perovskite solar cells (LFPSCs) because of its nontoxic nature and optoelectronic properties. However, the wide bandgap (2.2 eV) of the MA 3 Bi 2 I 9 perovskite‐like material is the major drawback, which may be responsible for poor light absorption and lower performance of the developed LFPSC devices. Thus, it is believed that the optical features of the MA 3 Bi 2 I 9 perovskite may be tuned using bandgap engineering approach.