Heteroepitaxial growth of $β-LiGaO2$ thin films on ZnO

High-quality interface between an insulator and ZnO as a wide-band-gap semiconductor should realize devices based on field-effect carrier modulation or superlattices having large band offset over 1 eV. We demonstrate that $LiGaO2$ could be a possible candidate for this purpose. Heteroepitaxy of $LiGaO2$ is demonstrated on ZnO films, giving atomically sharp interface and fairly good exciton-related optical properties in the ZnO under layer. Although slight distortion of a basal-plane hexagon with a lattice mismatch of about 3% in $LiGaO2$ gives multidomain epitaxial structure with relaxed lattices, a possible solution is proposed to realize coherent heterointerface.