Band Gap Shift and Electrical Conductivity of (Ag-xSnO₂)NPs-β-Carotene Thin Film

This research proposed to use β-carotene as a conducting polymer to encapsulate Ag-SnO₂ to enhance the electrical conductivity, so it becomes more new green technology. Initially, the synthesis of Ag and SnO₂ nanoparticles was performed by chemical reduction and a sol-gel method respectively. The (Ag-xSnO₂) nanoparticles with β-carotene composite were synthesized by the blending method and followed by deposition using a spin coating method. Samples of nanoparticles and films were characterized using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to obtain their structure, morphology, and size. Based on the analysis of XRD pattern, it was shown that the grain size of Ag and SnO₂ are 25.50 nm and 37.79 nm respectively. Optical properties of samples which were investigated by using UV-vis spectroscopy to find out the energy gap based on the Tauc plot method. It was found that that the energy gap of (Ag-xSnO₂)NPs-β-carotene thin film reduce which the average of ∼3.7 eV. It was also shown that inducing of SnO₂ nanoparticles could enhance the electrical conductivity of films with the increase of SnO₂. This combination of reducing the band gap and enhancing its electrical conductivity opens this composite for solar cell application. (paper)