Optical and electrical properties of CdO: Sn thin films for solar cell applications

Abstract

Tin doped Cadmium Oxide (CdO:Sn) thin films were successfully deposited by thermal evaporation in the Edward’s Auto 306 Magnetron Sputtering System. Their optical and electrical properties were studied using Solid Spec-3700 DUV Spectrophotometer and Four Point Probe respectively. The optical properties of CdO:Sn thin films showed high transparency in the visible region of the electromagnetic spectrum which varied with Sn doping, this makes CdO:Sn an excellent candidate for optoelectronic applications such as a window layer. Undoped Cadmium Oxide (CdO) thin films were also prepared for comparison with tin doped Cadmium Oxide thin films. Doped and undoped Cadmium Oxide had a transmittance of 70-85% and 50-89% respectively. Band gap energy for undoped CdO was 2.43eV while that of tin doped CdO ranged between 3.19-3.29eV for tin doping of 1-7%. Resistivity of undoped and Tin doped Cadmium Oxide ranged between 16-93Ωcm.