CRYSTALLINE PHASES AT THE P-TYPE TO N-TYPE TRANSITION IN CU-TERNARY SEMICONDUCTING-FILMS

We report here a study of the Raman spectra of ternary Cu-In-S and Cu- In-Se polycrystalline film compounds as a function of the x=[In]/{Cu][In]} ratio. Using these spectra we were able to identify, with high r esolution in x, the phases present in the films. We found that the sin gle phase of chalcopyrite CnInSe(2) exists over the fairly wide compos ition range of 0.48 less than or equal to x less than or equal to 0.55 , and that the lattice disorder increases with the increase of In cont ent. No such single phase range was found for the Cu-In-S films. Consi dering the electrical properties of these materials around x=0.5, it i s concluded that the native defect model accounts for the electrical p roperties of the Cu-In-Se films but does not account simply for the el ectrical properties of the Cu-In-S films. (C) 1996 American Institute of Physics.