A novel synthesis and characterization of transparent CdS thin films for CdTe/CdS solar cells

Abstract

We demonstrate the direct synthesis of CdS thin films by spin coating method with thiol-amine co-solvents system. Annealing of the films at various temperatures has been performed in the air using simple glass protector. The XRD patterns show a strong peak along (110) plane related to cubic lattice while two weak peaks at (002) and (100) planes indicate the hexagonal symmetry for the CdS thin films. The Raman peak at 305 cm−1 also confirms the formation of crystalline CdS thin films. The FTIR study also reveals the formation of CdS thin films. The SEM images reveal the surface uniformity and homogeneity of the CdS thin films. The EDX results indicate nearly stoichiometric CdS thin films. The optical band gap of CdS thin films is ~ 2.4 eV when coated at 2000 rpm and annealed at 300 °C for 5 min. These findings indicate that synthesized CdS films are potential candidates for solution-processed CdTe/CdS solar cells.