Investigation of electrodeposited CdTe thin films for solar cell development

Journal article, 2023

We report the growth of CdTe thin films using a wet-chemical electrochemical technique in an aqueous bath. The effect of bath temperature is investigated in detail on the various properties of the sample and the optoelectronic performance of the solar cell devices. A three-electrode technique was employed to deposit the samples at − 0.7 V concerning the Ag/AgCl reference electrode optimized by cyclic voltammetry measurements. The sample annealed at 450 °C for 20 min exhibited a polycrystalline cubic crystal structure of CdTe with an optical energy bandgap of ~ 1.45 eV. The Raman analysis reveals the growth of highly polycrystalline CdTe. All samples were highly compact and well-adherent to the substrate without pinholes. The annealed sample grown at a bath temperature of 50 °C exhibited a large globular grain size of ~ 1 μm. Furthermore, the stoichiometric (50:50) growth of Cd and Te was confirmed using EDAX for the sample grown at a bath temperature of 50 °C. A typical solar cell device, glass/FTO/CdS/CdTe/Au, was measured under dark and illuminated conditions with an input intensity of 100 mW/cm2 and showed a fill factor of ~ 50% and an efficiency of 2.65%. The solar cell parameters can be further improved by optimizing the surface treatment conditions using appropriate oxidizing and reducing reagents.