Simple and Productive Method to Develop Highly Sensitive and Fast Infrared Photodetector Using Spray Deposited Nanocrystalline PbS Thin Film

Abstract

This work demonstrates the development of a highly sensitive and fast infrared photodetector using a PbS thin film deposited using a simple and scalable method known as “spray pyrolysis”. An aqueous precursor solution was deposited on a glass substrate at 150 °C have a cubic phase of PbS. Silver electrodes with a 1 mm gap are drawn on the film to create photo-detector devices. Low resistive contact between the silver electrode and the PbS film is revealed from the linear I-V measurements performed in the dark and under light illumination. Under the illumination of a 100-watt tungsten lamp, the photo-responsivity, sensitivity, response time, and decay time of the PbS film were measured. The Ag/PbS/Ag photodetector device has a responsivity of 70 mA/W, a sensitivity of 200 at 30 V, and the best response and decay times of 6.4 and 15.6 ms, respectively. The photodetector device produced by this simple and low-cost fabrication method has a fast response and decay time.