Annealing methods were used to study as-grown B-doped films. The current-voltage characteristics of the films were also investigated. The conductivity was first examined in order to determine the effect of annealing upon B-doped films. The results indicated that the activation energy in as-deposited films (intrinsic or lightly B-doped) was equal to about 0.38eV. The activation energy had not changed after annealing. However, the activation energy of heavily doped films had changed appreciably to 0.014eV after annealing. Cathodoluminescence and Fourier transform infra-red spectroscopy were then performed in order to understand more clearly the correlation between the activation energy and the annealing treatment of B-doped films. The results showed that, in lightly B-doped films, the B atoms were effectively activated at substitutional sites. It was concluded that, in heavily doped samples, B was initially located in inactive sites (grain boundary, interstitial), and diffused into substitutional sites during annealing at 900C.

S.H.Chen, S.L.Chen, M.H.Tsai, J.J.Shyu, C.F.Chen: Journal of the Electrochemical Society, 1995, 142[12], L223-5