THERMAL-DECOMPOSITION OF TERNARY CHALCOPYRITE THIN-FILMS

Polycrystalline thin films of the ternary chalcopyrite semiconductors CuIn3Se5 and CuInSe2, prepared by a coevaporation process, have been investigated with the Temperature Programmed Desorption method (TPD). The desorbing species have been detected with a mass spectrometer for temperatures up to 750-degrees-C. Morphological changes have been observed with SEM and compositional data have been recorded before and after the heat treatments. The decomposition process has been found to start at about 500-degrees-C with outgasing of Se2 species, followed by the desorption of In2Se starting at 600-degrees-C. CuIn3Se5 thin films could be transformed totally to Cu2Se.