Laser engraving method to fabricate iodide and bromide-based perovskite photosensors

The bandgap tunability in methylammonium (MA) lead halide perovskites has motivated us to design a photoresistor array made of MAPbI3, MAPbBr1.5I1.5, and MAPbBr3. To pattern devices on the same substrate, a novel method of laser engraving the substrate was employed. In this method, first, an indium tin oxide (ITO) coated plastic substrate was laser engraved to make microchannels with a width of 50-100 µm. Capillary motion force was used to fill each channel with a different solution containing the perovskite precursors. The current-voltage characteristics of each sensor were studied under dark and light conditions. Light-emitting diodes with different wavelengths were used to study the response of each sensor to monochromic lights. The results are promising toward the fabrication of larger arrays of photosensors which potentially can be used for compact and integrated photospectrometers in lab-on-a-chip devices.