“…In contrast, the band gap shifted to G k-point for HBPI75 and HBPI100 perovskites. The HBPI0 has a band gap of 1.64 eV, which matches with the previous study and is close to the band gap of MAPI perovskites, [14] making HBPI0 a potential alternative OE material for MAPbI 3 perovskites in various applications like solar cells, LASER, LED, etc. The orthorhombic HBPI0 has a significantly less band gap than the hexagonal HBPI0.…”