The viability of alternative and nontoxic chlorine containing compounds for thermal treatment of ultrathin CdTe (≤1.0 μm) films

A detailed comparative analysis using alternative Cl compounds such as InCl2, MgCl2, SnCl2, and ZnCl2 along with CdCl2 was conducted in this study to assess their viability for the thermal treatment of ultrathin CdTe films. Similar or even better structural and electrical properties were found upon using InCl2, MgCl2, and ZnCl2 in thermal treatment than the conventional CdCl2. The film's bandgap is found to reduce upon the thermal treatment which varied in the range of 1.44-1.50 eV. A low amount of metal doping occurred in films' surfaces upon thermal treatment and influence the carrier concentration which varied from 7.32 × 1015-1.76 × 1017/cm3. The viability of the alternate materials was also investigated through the device simulation. All investigated results indicated that MgCl2 and ZnCl2 can be used in the current manufacturing technique instead of traditional CdCl2, which could reduce the environmental risk and production cost.