硅衬底对纳米ZnO/p-Si异质结酒精敏感性能的影响

摘要

采用射频磁控溅射的方法在不同电阻率的p型硅衬底上沉积氧化锌薄膜,制备了ZnO/p-Si异质结.通过X射线衍射(XRD)和扫描电镜(SEM)分析ZnO薄膜的物相结构和表面形貌.研究室温下不同电阻率的硅衬底对ZnO/p-Si异质结电流-电压特性和酒精敏感特性的影响.结果表明:ZnO薄膜结晶情况良好,具有高度的c轴择优取向,表面颗粒分布均匀；ZnO/p-Si异质结酒精敏感性依赖于p-Si衬底,当p-Si衬底的电阻率为10～20Ω· cm时,其气敏性能最强；该异质结在+4.0 V的偏置电压下,对0.024 g/L酒精气体的灵敏度为39.7％.%ZnO/p-Si heterojunctions were prepared by depositing ZnO films on p-Si substrates with different resistivities using radio-frequency magnetron sputtering. The raicrostructure of ZnO film was analyzed by X-ray diffraction and scanning electron microscopy. The current-voltage characteristics and ethanol gas sensing properties of the junctions were investigated at room temperature. The results show that the films crystallize well with high c-axis orientation, and the size and distribution of grains on the surface are uniform. The optimization of p-Si substrate resistivity is critical to enhance the ethanol gas sensitivity of ZnO/p-Si heterojunction. The ZnO/p-Si heterojunction with p-Si substrate resistivity of 10-20 ft ?cm exhibits the best ethanol gas sensing property. The junction shows the sensitivity of 39. 7% to 0. 024 g/L ethanol gas under+4 V forward bias voltage.