Growth of MgxZn1 − xO films using remote plasma MOCVD

MgxZn1 − xO films were successfully grown on a-plane sapphire (112¯0) substrates by remote plasma enhanced metalorganic chemical vapor deposition (RPE-MOCVD). Diethyl zinc (DEZn), bis-ethylcyclopentadienyl magnesium (EtCp2Mg) and oxygen plasma were used as source materials. By increasing Mg content in the films, the crystal structure was shifted through a mixed state from wurtzite to rock-salt with no significant segregation. Both optical absorption edges and emission peaks of MgxZn1 − xO films shifted to the higher energy by increasing the Mg content at room temperature, showing an alloy broadening. The Stokes' shift of wurtzite MgxZn1 − xO alloy films was quantitatively evaluated, resulting in a linear dependence on the absorption edge energy.