Development of flexible and highly efficient infrared photo-detector device using PbS thin film

Abstract

This research is focused on developing a simple, low-cost, flexible, and highly efficient infrared photodetector based on PbS thin film synthesized on polyethylene terephthalate (PET) substrate at 150 OC using the versatile spray pyrolysis technique. The SEM image, XRD, and optical absorption spectra showed the uniformly spread PbS thin film on PET substrate with a cubic crystal structure and optical band gap of about ∼ 1.8 eV, respectively. The photodetector device fabricated using silver electrodes on PbS thin film with a 1 mm electrode gap shows remarkably lower response and decay time of 3.7 and 18.3 ms and responsivity of 40 mA/W. This simple as well as low-cost fabrication technique provides a photodetector device fabricated on a non-toxic substrate with promising IR photodetection performance under ambient conditions and is found suitable for wearable devices to protect humans from getting exposed to IR radiation.