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

Abstract

A detailed comparative analysis using alternative Cl compounds such as InCl 2 , MgCl 2 , SnCl 2 , and ZnCl 2 along with CdCl 2 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 InCl 2 , MgCl 2 , and ZnCl 2 in thermal treatment than the conventional CdCl 2 . 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 × 10 15 -1.76 × 10 17 /cm 3 . The viability of the alternate materials was also investigated through the device simulation. All investigated results indicated that MgCl 2 and ZnCl 2 can be used in the current manufacturing technique instead of traditional CdCl 2 , which could reduce the environmental risk and production cost.