CHARACTERISTICS OF CHLORINE-DOPED ZNSE FILMS AND ZNSE-ZNS SUPERLATTICES GROWN BY HOT-WALL EPITAXY

Chlorine-doped (Cl-doped) n-type ZnSe films were prepared on GaAs(100) substrates by hot wall epitaxy (HWE) using ZnCl2 as a doping source. The electron concentration could be controlled from 8.4 x 10(14) Cm-3 to 2.8 x 10(19) cm-3 by varying the ZnCl2 temperature. ZnSe films with an electron concentration above 10(19) CM-3, having a donor-bound exc itonic photoluminescence emission (I2) without deep level emission wer e obtained for the first time. The activation energy of the chlorine d onor was estimated to be 26.7 meV from the photon energy of I2. The ex istence of Cl in the films was confirmed by SIMS. Moreover, the Cl-dop ed ZnSe-ZnS superlattices with high electron concentration on the orde r of 10(17) cm-3 and excitonic PL emissions associated with the free e xciton, were obtained for the first time.