Structural changes of CuGaSe₂ films during the three-stage process observed by spectroscopic light scattering

We have studied the three-stage deposition process of CuGaSe₂ (CGS) films, with the help of spectroscopic light scattering (SLS) in situ monitoring method. During the second stage (i.e. deposition of Cu, Se), an abrupt change from a two-layered structure to a single layer, together with a significant increase in the grain size, was observed in the vicinity of the Cu/Ga=1.0 point. Shortly before this abrupt change, a characteristic peak was observed by SLS, accompanied by a definitive change in depth-oriented distribution of Cu and Na.