Fabrication of high efficiency CdTe thin film solar cells using electrodeposition

The influences of CdTe and CdS film thicknesses and CdS pre-treatment on CdTe solar cell performances were investigated. The CdTe film thickness was varied from 2.2 to 5.3 /spl mu/m. The CdS film thickness was varied from 700 /spl Aring/ to 2500 /spl Aring/. The highest efficiencies were obtained with a CdTe thickness of 3.4 /spl mu/m and a CdS thickness of 1500 /spl Aring/. An increase of 2.7 mA/cm/sup 2/ in J/sub sc/ was observed as a result of CdCl/sub 2/ treatment of CdS, resulting from an improved spectral response in the wavelength range of 500-600 nm. CdCl/sub 2/ treatment of CdS affects CdTe-CdS interdiffusion and leads to differences in optical transmission of CdS films. X-ray diffraction studies indicated the full conversion of CdS into CdS/sub 1-y/Te/sub y/ ternary phase for films prepared with as-deposited CdS and very low concentration of CdS/sub 1-y/Te/sub y/ for films prepared with CdCl/sub 2/-treated CdS.