| 초록 |
Nonpolar a-plane ZnO film grown by a simple hydrothermal method has been grown and platinum Schottky metal diode on this film fabricated. ZnO has wide bandgap of 3.4 eV, which makes ZnO suitable material for UV detector due to the selective absorption of UV light. Also, ZnO with Schottky contact can be used as hydrogen sensor whose Schottky barrier height increases with amount of hydrogen exposed to active region of the diode. Furthermore, nonpolar a-plane ZnO based Schottky diode shows superior sensing to conventional polar c-plane ZnO due to higher affinity of oxygen to hydrogen. The Schottky barrier height of Pt Schottky contact on a-plane ZnO was measured to be 0.64 eV at room temperature and atmospheric pressure. After exposure of 4% hydrogen, the diode showed current increase due to Schottky barrier height reduction and current recovery right after hydrogen removal. For irradiation of UV lights, the device showed reliable current responses from electron-hole pair generations. |
