The effect of pH on the optical band gap of PbSe thin film with usability in the quantum dot solar cell and photocatalytic activity

This study is an attempt to provide a simple solution processed synthesis route for Lead Selenide (PbSe) nanostructure thin films using the chemical bath deposition (CBD) method which is commercially available in inexpensive precursors. In the CBD method, the preparation parameters play a considerable role to determine the nature of the final product formed. Known as two main factors, the effects of complex agent (PH) and time of reaction regarding the evolution of the configuration and the optical band gap of PbSe nanostructures with self-assemble arrays are investigated in this study. These preparation parameters were tuned to affect the nanostructured semiconductors with band gaps of around 1.4 eV where they could be used for the quantum dot solar cell. The films were characterized by X-ray diffraction (XRD), UV-visible spectroscopy for energy band gap estimation, and scanning electron microscopy (SEM) for morphology investigation as well as size distribution. The change in the pH alters the optical band gap from 3.56 to 1.4 eV. The exceptional photo-catalytic behavior from the increased visible light absorption supports the separation of photo-generated electrons and holes, where it also improves the photo-catalytic oxidizing species with PbSe nanostructured thin films.