Surface area, optical and electrical studies on PbS nanosheets for visible light photo-detector application

Abstract

Herein, we report the morphological, surface area and detailed electrical properties of PbS nanosheets. Scanning electron microscope elemental mapping confirms the formation of PbS and homogeneous distribution of Pb and S in final product. Morphology was confirmed as nanosheets by transmission electron microscopy. Specific surface area was found to be ∼7 m2 g-1 through Brunauer-Emmett-Teller analysis. The diffused reflectance spectrum was measured and optical energy gap was estimated ∼1.284 eV. Such a value of the energy gap makes it suitable for solar cell and other optoelectronic applications. An increase in photosensitivity with increasing the light intensity was observed due to an increase in the generation rate of photo-carriers. The recombination value is calculated ∼0.59, it indicates that the defect states continuously distributed in the energy gap. The differential lifetime increases with time and also the life time of the current carrier is enhanced with light intensity.