Thin films have drawn the attention of many researchers because of their numerous applications in various fields. The main interest in thin films is due to the important properties that differ from those of the bulk. The book consists of five chapters. The PbSe, PbTe and SnO2 thin films were grown by chemical bath deposition (CBD) technique. The XRD, SEM, UV-Visible absorption, dielectric studies and photoconductivity measurements were used to characterize the prepared films. The crystal structure and crystallite size of the thin films were determined from the X-ray diffraction (XRD) patterns. The optical properties were studied by the Ultraviolet-Visible (UV-Vis) absorption spectrum. The morphology was studied using Scanning electron microscope microscopy. The dielectric properties of thin films such as the dielectric constant, the dielectric loss and AC conductivity studies were studied in the frequency range of 50Hz-5MHz at different temperatures. Further, electronic properties such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability of the thin films were calculated.