First Principles assisted modeling to understand Chlorine passivation of CdTe grain boundary

A computational study on cadmium telluride (CdTe) (111)/(220) grain boundary was performed using a first-principles approach. Cadmium chloride (CdCl
₂
) treatment of CdTe based solar cells has proven to be highly beneficial for device performance. Published literature suggests incorporation of chlorine at Te site (Cl
_Te
) in CdTe grain boundaries. Density Functional Theory was therefore used to identify the mechanisms responsible for enhancing CdTe device performance after CdCl
₂
treatment. The computational model explains the formation of local p-n-p junctions through field effect passivation after inclusion of Cl
_Te
, which significantly improves CdTe device performance by mitigating recombination at the interface.