Layered and Pb-Free Organic–Inorganic Perovskite Materials for Ultraviolet Photoresponse: (010)-Oriented (CH₃NH₃)₂MnCl₄ Thin Film

Organic–inorganic lead perovskite materials show impressive performance in photovoltaics, photodetectors, light-emitting diodes, lasers, sensors, medical imaging devices, and other applications. Although organic–inorganic lead perovskites have shown good performance in numerous fields, they contain toxic Pb, which is expected to cause environmental pollution in future large-scale applications. Thus, the photoelectric properties of Pb-free organic–inorganic perovskite materials should be developed and studied. In this paper, we report on the photoresponse of Pb-free organic–inorganic hybrid manganese perovskite (CH 3 NH 3 ) 2 MnCl 4 . To the best of our knowledge, this study demonstrates the first time that organic–inorganic hybrid manganese perovskites are used for this type of application. We found that the solution-processed MA 2 MnCl 4 thin film tends to be oriented along the b -axis direction on the TiO 2 surface. The evident photoresponse of the FTO/TiO 2 /MA 2 MnCl 4 /carbon electrode devices was observed under 10–30 Hz flashlight frequencies and a 330 nm light beam. This simple, green, and low-cost photoresponsive device is beneficial for the future industrial production of optical recorders and optical memory devices.