In-situ HT-XRD study of CdTe thin-films during CdCl2 heat treatment

Effects of the heat treatment of the CdCl2 layer on the phase transition occurring during recrystallization of sputtered CdTe thin-films were investigated and a detailed observation of recrystallization of the CdTe (111) plane was carried out. The spatial distribution of the (111) plane as a function of the azimuthal and tilt angles rearranged to the direction parallel to the film growth depending on annealing temperatures. This is deeply bound up with the realignment of the (111) plane to a direction that is out of plane rather than with fresh nucleation and crystallization of the CdTe phase. The heat treatment also leads to the formation of larger grains with column structures, indicating merging of neighboring grains by reducing the grain boundary energy barrier. The grain growth of CdTe along (111) plane during CdCl2 heat treatment is caused by realignment of the CdTe (111) plane to a direction out of plane.