MgxZn1-xO as a II-VI widegap semiconductor alloy

We propose a widegap II-VI semiconductor alloy, MgxZn1-xO, for the fabrication of heteroepitaxial ultraviolet light emitting devices based on ZnO. The c-axis oriented MgxZn1-xO films were epitaxially grown by pulsed laser deposition on ZnO epitaxial films and sapphire (0001) substrates using ceramic targets. Solid solution films were prepared with Me content up to x=0.33, achieving a band gap of 3.99 eV at room temperature. MgO impurity phase segregated at x greater than or equal to 0.36. Lattice constants of MgxZn1-xO films changed slightly (similar to 1%), increasing ina axis and decreasing in c-axis direction with increasing x. These films showed ultraviolet photoluminescence at energies from 3.36 (x=0) to 3.87 eV (x=0.33) at 4.2 K. (C) 1998 American Institute of Physics. [S0003-6951(98)04219-3].