A study of the CdTe treatment with a Freon gas such as CHF2Cl

In order to obtain high efficiency CdS/CdTe solar cells, a CdTe heat treatment in a Cl2 containing atmosphere is necessary. Normally, this treatment is done by depositing a CdCl2 thin film on top of CdTe and by heating the system in air at a fixed temperature. This step is disadvantageous in a large scale fabrication process because it involves the use of CdCl2 that it is difficult to be handled. We replaced this treatment by using a gas (HCF2Cl) that is stable, inert and not toxic at room temperature and eliminates the step of CdCl2 evaporation and subsequent chemical etching.