Optical Properties of MgxZn1-xO Alloy and Mg0.08Zn0.92O/ZnO Heterostructure Grown by P-MBE
Mg_xZn_(1-x)O单晶薄膜和MgZnO/ZnO异质结构的光学性质

Optical properties of Mg xZn 1-xO alloy thin films and Mg 0.08 Zn 0.92O/ZnO heterostructure are reported,which are fabricated on c- plan s sapphire(Al 2O 3) substrates by plasma assisted molecular beam epitaxy (P-M BE).X-ray diffraction indicates the Mg xZn 1-xO films with the ( 002) preference reflection of hexagonal wurtzite structure when x value is c hanged from 0 to 0.14.Reflection high-energy electron diffraction (RHEED) and X-ray double crystal diffraction spectra show that the samples are single-crys tal films.Photoluminescence spectra at room temperature show an intense ultravio let emission,which shifts to high-energy side with increasing x values.This UV emission is attributed to the recombination of donor bound excitons.Absorpti on and PL spectra at RT of Mg 0.08Zn 0.92O/ZnO heterostructure show th at two absorption edges and two emission peaks,respectively.The two peaks are co nsidered to be from the bound exciton transition of MgZnO and the free exciton t ransition of ZnO,respectively.