(a) Ultraviolet–visible absorbance spectrum of inorganic dual-phase perovskite film; inset: photographs of the inorganic perovskite film on glass substrate under ambient conditions (left) and under ultraviolet illumination (right). The films are sized 2.5 ×1.5 cm². (b) Corresponding magnified and normalized plots of one response cycle for estimating the rise and fall times of the photodetector.^[76]