InSb-ZnO:Ge nanocomposite thin films: One-step synthesis, structural, optical, and electrical properties

One-step synthesis of the composite thin film with InSb nanocrystals embedded in ZnO doped with Ge was investigated. The films were deposited on water-cooled substrate by radio-frequency sputtering using a target of ceramic ZnO disc with InSb and Ge chips and subsequently heat-treated in vacuum. The composites exhibited a shift in optical absorption edge due to a presence of InSb nanocrystals. Elemental mapping using energy dispersive X-ray microscopy revealed that the added Ge was selectively located in ZnO. The solubility limit of Ge in ZnO was 2 at.% at an annealing temperature of 873 K. Electrical resistivity of the composite was reduced to 6.6 × 10-3 Ω cm at an annealing temperature of 773 K due to doping with Ge. Simultaneous addition of InSb and Ge to ZnO therefore provided the different functionalities of the optical absorption shifts and relatively low electrical resistivity.