Fabrication of low-cost and fast-response visible photodetector based on ZnS:Mn/p-Si heterojunction

Abstract

Present communication reports fabrication of visible sensor based on ZnS:Mn/p-Si heterostructure. Herein, Pure and Mn+2 doped ZnS nanocrystalline thin films structures have been deposited on the p-type silicon (Si) substrates using chemical bath deposition technique. The structural, morphological, and optical analysis have been systematically examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV-VIS) and photoluminescence (PL) spectroscopy respectively. Further, the use of the deposited ZnS structures for optical and electrochemical applications was studied using Commission International DeI’Eclairage (CIE) and electrochemical analysis. The electrical properties of the fabricated ZnS:Mn/p-Si heterostructures were explored by illumination visible light of intensity 30 mW/cm2 and calculated all the essential photodetection parameters using the current-voltage (I–V) and current-time (I-T) plots. Enhanced sensitivity (5.01×102), responsivity (7.9 ×10−2 mA/Watt), linear dynamic range (54.03 dB) and external quantum efficiency (16.32%) was observed in ZnS:Mn/p-Si heterostructure device as compared to ZnS/p-Si heterostructure. Hence, the ZnS:Mn/p-Si device shows improved and enhanced optoelectronic performance in comparison to device fabricated using pure ZnS.