AFM and Optical Study of Graphene Oxide and In2S3/GRO: Effect of Thickness

Continuous efforts have been done to develop high quality Graphene in large area for both research purposes and with a view to possible applications. Although most of the research progress has been made in understanding the structure, processing and properties of GRO/GRO-based compound, there is significantly more to be explored and exploited given the highly versatile physical properties of the material. In this work we report an efficient and easily accessible route to synthesize graphene oxide using modified Hummer's method, indium sulphide and In2S3-GRO composites by a hydrothermal process. The films were fabricated in various thicknesses, which allows styding the effect of the thickness on the material properties. Surface morphology of the samples was investigated using atomic force microscopy (AFM), which showed that films had a continuous coverage with a smooth surface. The optical characteristics of the deposited films were obtained from the analysis of the transmission and reflectance spectral data over the wavelength range of 300-1800 nm. The optical absorption data yielded a direct band gap energy of 3.4eV for GO sample, while the bad gap varies from 3.7 to 3.0 eV for the In2S3/GO-based samples depending on the thickness of the the In2S3 itself. This work provides new insights into utilizing In2S3/GO composites for energy conversion.