Solution-processed visible-blind UV-A photodetectors based on CH3NH3PbCl3 perovskite thin filmsElectronic supplementary information (ESI) available. See DOI: 10.1039/c7tc00639j

In this contribution, methylammonium lead trichloride (CH 3 NH 3 PbCl 3 ) perovskite thin films were fabricated via a two-step spin coating and solvent-vapor-assisted thermal annealing method at low temperature. The films exhibited a cubic crystalline structure and pinhole-free morphologies. The possible charge traps were investigated via the analysis of photoluminescence (PL) spectra of perovskite films prepared with different lead chloride (PbCl 2 ) precursor concentrations while maintaining the same concentration of methylammonium chloride (CH 3 NH 3 Cl). Prototypical ultraviolet (UV) photodetectors with the structure of ITO/CH 3 NH 3 PbCl 3 /poly(triaryl amine) (PTAA)/Al were fabricated and showed a low dark current density of 1.60 × 10 −5 mA cm −2 under a reverse bias of −1 V, a strong photoresponse in the 300-400 nm region, and a high UV-visible rejection ratio of up to 500 under a bias of 0 or −0.5 V. All the results demonstrated that low-temperature solution-processed CH 3 NH 3 PbCl 3 perovskite thin films offer great potential for making flexible, lightweight visible-blind UV-A photodetectors. Solution-processed visible-blind UV-A photodetectors based on smooth, pinhole-free CH 3 NH 3 PbCl 3 perovskite thin films with a high UV-visible rejection ratio.