Typical structures of heterojunction photovoltaic cells were prepared by sequential electrodeposition of II-VI semiconductor thin films on a transparent conductor, SnO2 on glass. The structures comprised a wide bandgap, window, ZnSe or ZnTe, a medium bandgap light absorber, CdTe, and an ohmic back contact. It is demonstrated that low incidence angle X-ray diffraction (LIXD) can be successfully used as a process monitoring tool, featuring non-destructive depth profiling and phase characterization of such thin film structures. LIXD results are compared to Secondary Ion Mass Spectroscopy (SIMS) and Scanning Electron Microscopy (SEM) data. Both, SIMS and SEM, corroborate the LIXD results as to layer sequence and presence/absence of intermixing. (c) 2005 Elsevier B.V All rights reserved.