“…HAPI showed an extremely strong AC (over 10 4 cm −1 ) in the shorter wavelength of the visible region, making them perfect for various OE applications [ [43] , [44] , [45] , [46] ], e.g., LASER, solar cells, LED, etc. However, the AC is comparatively lower than the MAPI perovskites observed in theoretical and practical studies [ [47] , [48] , [49] ]. The absorption curve is analogous to previous research [ 24 ].…”