“Thin film and nano technology” has convincing impact on standard of life now. No one can deny the effect of “Thin film & Nano technology” upon the modernization of industry. This book reveals advance level nano research in electrical characterization, variable range hopping modeling and hall effect measurements of cadmium sulfide and zinc oxide nano materials. Their importance as Photovoltaic and Energy Materials is also discussed. I-V characterizations for these films under light and dark conditions showed features which is responsible for its applications as photovoltaic materials. The resistivity of ZnO and CdS thin films have followed the hopping model which also confirmed the semiconductor like nature of these materials. As for ZnO and CdS films, hopping distance decreased while hopping energy increased linearly with rising temperature. Both these materials have followed necessary conditions for Mott’s VRH mechanism. The said model is applied to dc electrical resistivity data.