DIRECT EVIDENCE FOR DIFFUSION AND ELECTROMIGRATION OF CU IN CUINSE2

Cu diffusion in chalcopyrite CuInSe2 was studied directly, using Cu-64 as a radioactive tracer. For diffusion from a thin surface layer, the Cu diffusion coefficients at 380 and 430 degrees C, were found to var y from 10(-8) to 10(-9) cm(2)/s. In case of diffusion from a volume so urce at 400 degrees C, a value of 10(-10) cm(2)/s was calculated from diffusion profiles. Electromigration of Cu was demonstrated, by applyi ng a strong electric field to a sample and following the redistributio n of Cu-64, that had been thermally diffused into the sample, prior to electric field application. (C) 1997 American Institute of Physics. [ S0021-8979(97)03321-5].