Paper based photo-detector using nano-crystalline lead sulfide thin film

Abstract

In this paper, we report an extremely low cost and highly efficient method for fabrication of visible light photo-detector using nano-crystalline lead sulfide (PbS) thin film. The film was fabricated on 300 GSM paper via spray pyrolysis technique at 100 0C. Structural and morphological analysis of the film confirms the nano-crystalline nature of PbS with size ~ 50 nm and uniform coating of PbS on paper. Photo-detector devices are prepared by drawing contacts using 4B pencil on the film by keeping a gap of 1 mm between electrodes. Photo-detection property of a nano-crystalline PbS thin film under visible light illumination show linear I-V suggesting low resistive contact between graphite electrode and PbS film. The photo-sensitivity measurements reveal excellent sensitivity of ~ 103 at 20 V. For this graphite/nanoPbS/paper photo-detector, the best rise and decay time is observed to be 7 and 16 ms, respectively. This simple and low cost fabrication method results in highly stable and sensitive photo-detectors device, which have fast response and decay time.