Cubic Mg_xZn_(1-x)O Films Grown on Si (111)

Epitaxy of the cubic MgxZu1-xO thin films on Si (111) was achieved by the reactive electron beam evaporation for the first time. Energy dispersive x-ray detection (EDX) and x-ray diffraction (XRD) were employed to characterize the as-grown films. The orientation of cubic MgxZn1-xO films relies on the growth temperature and the highly (200) oriented MgxZn1-xO films are attainable only at the optimal growth temperature of about 200℃. Photoluminescence excitation (PLE) spectroscopic measurement demonstrates that the optical absorption band edge of the cubic MgxZn1-xO is at 4.20eV, which is 3.50eV lower than the band gap of MgO. Furthermore, XRD measurements indicate the lattice mismatch between cubic MgxZn1-xO and MgO is only 0.16%. The successful growth of high quality MgxZn1-xO renders the fabrication of cubic phase MgxZn1-xO/MgO multiple quantum wells possible.