PHOTOLUMINESCENCE PROPERTIES OF ZNTE LAYERS GROWN BY PHOTO-ASSISTED METALORGANIC VAPOR-PHASE EPITAXY

Effects of light illumination on the photoluminescence (PL) properties of ZnTe has been investigated by using epitaxial layers grown with di fferent carrier gases, transport rate of source materials and light so urces or by introducing triethylaluminum (TEAl) as a dopant. Free exci ton emission can be observed in only the epitaxial layers grown with i llumination under H-2 atmosphere, implying that the illumination is ef fective for the growth of good quality ZnTe layers. The illumination s trengthens the transition due to excitons bound to donor impurities, n amely Cl which is substituted into Te lattice site, at low substrate t emperature. These effects are closely related to the use of photons ha ving an energy higher than the bandgap of ZnTe. It seems that the phot o-assisted metalorganic vapor phase epitaxy (MOVPE) technique also bri ngs about the effective formation of Al donor by suppressing the gener ation of the complex of Al and Zn-vacancy in the ZnTe epitaxial layer.