Deep-level transient spectroscopy and thermally stimulated capacitance studies of bulk Te- Se-, and S-doped samples revealed the presence of deep-levels which were intrinsic to the dopant species. The trap densities in Te- and Se-doped samples were found to be at least 2 orders of magnitude lower than the shallow donor concentration. The deep-level transient spectrum of S-doped material revealed a DX-like nature, in which the trap concentration was comparable to that of the shallow donor concentration. However, the Te- and Se-related levels did not exhibit DX-like characteristics. The deep-level transient spectroscopic and thermally stimulated capacitance data were in good agreement with each other.

P.S.Dutta, K.S.R.K.Rao, K.S.Sangunni, H.L.Bhat, V.Kumar: Applied Physics Letters, 1994, 65[11], 1412-4