Epitaxial growth and characterization of Cl-doped ZnSe layer by MBE

Chlorine-doped ZnSe grown by using molecular beam epitaxy was studied. It was found that the RHEED patterns observed for three azimuths changed from streaky to spotty patterns with the increase of the ZnCl2 cell temperature. The donor-bound exciton emission dominated in the chlorine-doped epitaxial films, and the emission line did the blue shift with the increase Of the ZnCl2 beam intensity. Both the emission peak intensity and the net donor concentration attained a maximum value, and then decreased together with increasing ZnCl2 beam intensity. These results were caused by the degradation of crystallinity due to excess chlorine atom on the growth surface. Moreover, they increased again by supplying the ZnCl2 beam without epitaxial growth. It indicated that the chlorine atoms could diffuse into the ZnSe epilayer by the ZnCl2 beam irradiation. (C) 2002 Elsevier Science B.V. All rights reserved.