Grain boundary character and recombination properties in CdTe thin films

In this work we present a correlation between the structural and electro-optical properties of grain boundaries in CdTe thin films deposited by vapor transport technique. We were able to identify different types of grain boundaries using electron backscatter diffraction (EBSD), and investigated their recombination properties by cathodoluminescence (CL). The objective is to investigate the existence of “good” and “bad” boundaries in CdTe thin films, which will provide guidance for the growth of better films in the future. The crystallographic orientation, grain size, and relative fraction of different boundaries were determined by EBSD. For the comparison study, the grain boundaries were colored according to their character, and compared to the CL spectra. By applying focused ion beam (FIB) marks, we were able to analyze CL and EBSD maps taken at exactly the same areas. We present a correlation between the types of boundaries with recombination.