Growth of ZnO/Ga2O3 and Ga2O3/ZnO heterostructures on c-Al2O3 substrate using pulsed laser deposition

Growth of ZnO/Ga2O3 and Ga2O3/ZnO heterostructures on c-Al2O3 substrate is demonstrated using pulsed laser deposition route. Based on the structural and surface morphological investigations hypothetical model explaining the respective growth is proposed. The template (i.e. Ga2O3/Al2O3 and ZnO/Al2O3) used to grow the final film are observed to control the overall micro structural, electrical as well as optical properties of these heterostructure. For e.g. broad UV emission is observed for Ga2O3 film deposited on the ZnO/Al2O3 substrate, whereas expected near band-edge emission is reported for ZnO film deposited on Ga2O3/Al2O3 substrate. Various emission processes involved in harvesting the UV-blue emission especially for Ga2O3/ZnO/Al2O3 heterostructure is explained by proposing the band diagram schematic.