Photo-induced conduction behaviour of chemically synthesized copper- doped lead sulphide hexapod

Abstract

A hexapod-like structure of pure and copper-doped lead sulphide was synthesized by the chemical bath deposition technique. Subsequently, the synthesized structure was analysed through XRD, FESEM, UV–Vis and FTIR spectroscopy. The UV–Vis spectra showed a band gap exceeding 5 eV, a significant variation from the previously reported values. The investigation encompassed the study of photoconductivity switching behaviour of the samples. The results showed that the exposure to UV illumination substantially increases the photo-current. Also, the Ohmic current-voltage characteristic of the pure sample gets transformed to non-linear in the case of the doped sample. This has been attributed to the formation of intermediate states in the forbidden gap as well as the formation of local junctions between host and dopant atom. The optical switching characteristics of samples were also studied and the decay has been well-fitted with second-order exponential decay. This study is a pioneer investigation of photoconductive traits of copper-doped lead sulphide hexapod-like nanostructures.