CHARACTERISTICS OF LI-DOPED AND CL-DOPED ZNTE GROWN BY MOLECULAR-BEAM EPITAXY

We found that the carrier concentration of Li-doped ZnTe, grown at growth temperature (T(g)) of 320-degrees-C, increased with rising the Li-cell temperature (T(Li)) below 220 and above 260-degrees-C, and decreased between 220 and 260-degrees-C. Both the acceptor and donor concentration of the T(Li) = 300-degrees-C sample were estimated to be smaller than those of the T(Li) = 220-degrees-C sample. We also found by PL spectra that only when the film was grown at T(Li) = 220-degrees-C, I1Li was replaced by an A(Li-Li) band. These properties above T(Li) = 220-degrees-C can be explained if we assume that the electrical activity of Li in ZnTe decreases drastically above T(Li) = 220-degrees-C. We also investigated the PL spectra of Cl-doped ZnTe. The VI-II ratio and T(g) dependence of PL spectra indicated that the films with better crystallinity were grown under Te-rich conditions above T(g) = 300-degrees-C.