Coherently coupled ZnO and VO ₂ interface studied by photoluminescence and electrical transport across a phase transition

We have investigated the photoluminescence and electrical properties of a coherently coupled interface consisting of a ZnO layer grown on top of an oriented VO ₂ layer on sapphire across the phase transition of VO ₂. The band edge and defect luminescence of the ZnO overlayer exhibit hysteresis in opposite directions induced by the phase transition of VO ₂. Concomitantly the phase transition of VO ₂ was seen to induce defects in the ZnO layer. Such coherently coupled interfaces could be of use in characterizing the stability of a variety of interfaces in situ and also for novel device application.