基于p^+-Si与n-ZnO纳米线的p-n异质结的制备及其性质研究

Synthesis and Electrical Properties of p^+-Si/n-ZnO Nanowires Heterojunction

利用CVD蒸汽俘获法,在p+硅片上制备了垂直生长的n型ZnO纳米线阵列,用XRD和SEM分析了样品的结构与形貌。测试发现样品的I-V曲线符合典型的p-n异质结特性,正向开启电压为0.5 V,反向饱和电流为0.02 mA。计算了异质结的理想因子η,发现当异质结两端偏压在0 V^0.3 V的低压区域,理想因子为1.85,而在0.3 V^0.8 V的高偏压区域,理想因子为8.36。解释了理想因子偏高的原因是由于金属-半导体接触以及ZnO纳米线与p+-Si界面存在缺陷。

Vertically aligned ZnO nanowires were synthesized on the p^＋ silicon chip by modifying the chemical vapor deposition（CVD） process with a vapor trapping design to produce a heterojunction. Scanning electron microscopy （SEM） and X-my diffraction （XRD） was used to characterize the morphology and structure of as-obtained heterojunction.The rectifying characteristics of the p-n heterojunction composed of ZnO nanowires and a p^＋ silicon chip were observed.The positive turn-on voltage was 0.5 V and the reverse saturation current was 0.02 mA. The value of the ideality factor of the heterojunction is 1.85 in the low bias voltage range of 0 V - 0.3 V and 8.36 in the high voltage range of 0.3 V- 0.8 V.The reason is the presence of the nonlinear metal-semiconductor contact and defects in the interface of heterojunction.