Procedure to obtain higher than 14% efficient thin film CdS/CdTe solar cells activated with HCF2Cl gas

This work reports a process used to obtain CdS/CdTe thin film solar cells with high efficiencies between 14% and 14.6%. The procedure consists of sequentially depositing by RF sputtering and close space sublimation (CSS) of several layers onto a glass substrate, configured as glass/ITO/ZnO/CdS/CdTe/Cu/Mo. The CdTe layer was deposited by CSS at low substrate temperature (500 °C) under Ar–O2 atmosphere and the activation process is performed with a mixture of Freon gas (HCF2Cl) and other gases.

Highlight
► We report a process to obtain CdS/CdTe solar cells with 14% efficiency.
► Almost all films are deposited by RF sputtering and CdS is not treated intentionally.
► The CdTe film is deposited by CSS at 500 °C, under Ar–O2 mixture atmosphere.
► We use HCF2Cl gas for activation treatment.
► Our process permits a reproducibility of 90%.