Low-temperature growth of ZnO films by using low-pressure MOCVD with a single-source precursor

Abstract

C-axis-oriented ZnO film have been successfully grown on GaAs (111) at a substrate temperature of 160 degrees C by using metalorganic chemical-vapor deposition(MOCVD) with a single-source precursor, methylzinc isopropanolato [CH(3)ZnOPri]. Photoluminescence (PL) measurements at low temperature were carried out for an optical evaluation of the grown thin films. The PL spectrum exhibited four emission peaks : 3.371 eV, 3.33 eV, 3.26 eV, and 3.19 eV. The peak at 3.371 eV was ascribed to free exciton (FE) emission, and the peak at 3.33 eV was due to shallow donor-to-acceptor transitions while those at 3.26 eV and 3.19 eV were due to LO-phonon replicas. The estimated LO-phonon energy was 70 meV.