Photoluminescence study of gallium arsenide irradiated with 15 MeV alpha particles

Gallium arsenide wafers were irradiated at room temperature with 15 MeV alpha particles and fluences in the range 10/sup 10/ to 10/sup 14/ /spl alpha//cm/sup 2/. This experiment extends the previous investigation of the same samples irradiated by 2.5, 5.0, and 10 MeV to 15 MeV, at which energy nuclear transmutations occur, and were observed via /spl gamma/ ray analysis, but no definitive effects of transmutations on photoluminescence measurements were observed. The gallium vacancy introduction rate b(V/sub Ga/) and silicon at the arsenic site introduction rate b(Si/sub As/) due to 15 MeV alpha particles were measured by low temperature photoluminescence spectroscopy and found to be (2.3/spl plusmn/0.8)/spl times/10/sup 3/ and (1.5/spl plusmn/0.3)/spl times/10/sup 3/ cm/sup -1/ respectively. The theoretical vacancy introduction rate, as calculated by taking into account only primary interactions, is (1.07/spl plusmn/0.02)/spl times/10/sup 3/ cm/sup -1/.