The structural characteristics of thin films which had been grown by organometallic vapor phase epitaxy and had been heavily implanted with Cl ions (5 x 1015 to 1016/cm2) were investigated by using ion beam techniques, X-ray diffraction, and Raman spectroscopy. It was found that, although the as-implanted layers were severely damaged, no amorphous layer formed at doses as high as 1016/cm2. Crystalline damage in the layers was not fully removed, even after annealing at 700C for 10s. The use of ion channelling revealed that, after annealing, over 50% of the Cl atoms were substitutionally placed in the lattice and were preferentially located at Se sites. However, a significant fraction of the substitutional Cl was found to be slightly displaced from the normal Se sites. The projected displacement was found to amount to about 0.02nm. Electrical and Raman spectroscopic data suggested that a large concentration of Zn vacancies was present in the annealed samples. It was suggested that the Cl displacement in, and the low conductivity of, these samples were due to the formation of (ClSe-VZn) complexes.

K.M.Yu, J.W.Ager, E.D.Bourret, J.Walker, W.Walukiewicz: Journal of Applied Physics, 1994, 75[3], 1378-83