Study of CdS/CdTe solar cells activated with an oxygen–CHClF2 gas mixture

• The CdTe cell activation effect using an O2–CHClF2 mixture was investigated.
• The photovoltaic cells parameters were considerably improved by O2–CHClF2 treatment.
• PL spectra indicate a better intermixing region after oxygen incorporation.
• This activation method achieves homogenous and repeatable cells.

CdTe solar cells were activated by using Argon, Argon–CHClF2 and Argon–Oxygen–CHClF2 gas mixtures respectively. The solar cells structures ZnO/CdS/CdTe were grown onto commercial indium tin oxide. Both ZnO and CdS thin films were deposited using rf-sputtering. The CdS layer, grown in Argon atmosphere, was not intentionally treated before the CdTe thin film was deposited using a conventional closed space sublimation technique. The influence of different gas mixtures annealing in the illuminated and darkness J–V curves, EQE and photoluminescence spectra are shown and discussed for each experiment.