The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure.

The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O 2 pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm 2 . This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O 2 flow. Through this method, the compact and uniform CdTe film (30 × 40 cm 2 ) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm 2 ) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density ( J sc ) of the cell is 26.9 mA/cm 2 , open circuit voltage ( V oc ) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film. [ABSTRACT FROM AUTHOR]