Annealing effects of Ga2O3–ZnO core-shell heteronanowires

We prepared ZnO-coated Ga2O3 nanowires and investigated changes in the morphological, structural, and photoluminescence (PL) characteristics resulting from application of a thermal annealing process. With the thermal annealing at 800 °C, defect-associated PL peaks (2.2 and 2.6 eV) have been intensified with respect to the UV peak, and a new 2.8 eV-peak has been generated. Possible emission mechanisms are also discussed.