Fabrication of a transparent ultraviolet detector by using n-type Ga2O3 and p-type Ga-doped SnO2 core-shell nanowires

This study investigates the feasibility of synthesizing high-density transparent Ga2O3/SnO2:Ga coreshell nanowires on a sapphire substrate at 1000 degrees C by VLS. The doping Ga concentrations are 0.46, 1.07, 2.30 and 17.53 atomic%. The XRD spectrum and HR-TEM reveal Ga2O3 and SnO2 as having monoclinic and tetragonal rutile structures, respectively. Experimental results indicate that the XRD peak shift of SnO2 to a larger angle increases with the increasing amount of Ga doping. According to the CL spectrum, SnO2 and Ga2O3 peak at approximately 528-568 nm and 422-424 nm, respectively. The maximum quantum efficiency of Ga2O3/SnO2:Ga core-shell nanowires is around 0.362%. The UV light on-off current contrast ratio of Ga2O3/SnO2:Ga core-shell nanowires is around 1066.7 at a bias of 5 V. Moreover, the dynamic response of Ga2O3/SnO2:Ga core-shell nanowires has an on-off current contrast ratio of around 16. Furthermore, the Ga2O3 region functions similar to a capacitor and continues to accumulate SnO2:Ga excited electrons under UV light exposure.