CsPbBr3-based photodetector with a multilayer architecture and asymmetric metal electrodes

In this work, the fabrication of inorganic perovskite thin films (CsPbBr 3 ) and the construction of low-cost, high-response electronic photodetectors based on this material are presented. The films were synthesized by thermal evaporation in a high vacuum using CsBr and PbBr 2 , showing a single-phase composition, high uniformity in grain sizes with an average value of 1.17 μm, and good substrate coverage, which favors electrical transport. Reflectance and transmittance analyses were performed, obtaining an optical band gap of E g = 2.36 eV and an absorption coefficient of α ≈ 10 4 c m − 1 , comparable to semiconductors like GaAs and CdTe. A planar Au/CsPbBr3/Au photodetector prototype was built to measure the electrical response under UV illumination of 400 nm at power levels between 0 and 63 mW/cm 2 , and another with asymmetric Au/CsPbBr3/Ag electrodes forming a Schottky junction to create a self-powered photodetector. Additionally, a multilayer system Au/TiO2/CsPbBr3/P3HT/Au was developed, coupled to a low-cost electronic system to measure the voltage response of each prototype.