On the redistribution of 20 keV lithium in CuInSe2

Twenty keV Li+ was implanted at room temperature into p- and n-conducting s ingle crystalline CuInSe2 at fluences of 3.2 x 10(15) and 3.2 x 10(16) cm(- 2), respectively. The lithium depth profiles were measured using the neutro n depth profiling technique. The diffusional deviation of the profiles from the ballistic expectation was simulated by a numerical computer calculatio n. From these examinations it is concluded that (a) lithium suffers considerable radiation-enhanced mobility during the imp lantation process, (b) the radiation-enhanced Li diffusion depends somewhat on the conductivit y state of CuInSe2, (c) the radiation-enhanced Li diffusion decreases with increasing implantat ion fluence, (d) whereas at the lower fluence, Li shows some thermal mobility, the latte r is negligible after high fluence implantation. The diffusional redistribution can be described in all cases reasonably wel l by depth independent diffusion without trapping, and insofar differs from previous examinations of hydrogen in CuInSe2. (C) 1999 Elsevier Science B. V. All rights reserved.