Cadmium sulfide doped with silver as CO2 gas sensor using pyrolysis technique

Abstract

The monitoring of CO2 in our life safety, industrial, and chemical laboratory
applications make it an inspiring task. The chemical spray pyrolysis technique
was used to prepare CdS/Ag thin films. The nanocrystalline cadmium sulfide
thin films were doped with Silver at different doping concentrations (0%, 2%,
and 4%). The morphologies, structures, and gas sensing properties of CdS/Ag
films are presented. The samples were characterized using X-ray diffraction
(XRD) and atomic force microscope (AFM). The XRD results show that the
films are a polycrystalline composition and hexagonal type with a favoured
orientation along (111) direction. The average grain size (nm) of AFM is
between 75 and 55 nm. As a result, Ag doping changes the sensitivity of the
samples respectively with the percentage of doping with time. The synthesis
samples show controlling sensitivity and the small response of sensitivity are
the key point in this study.