硅纳米线的可控生长及光电性能的研究

发布时间：2018-05-16 05:14

  本文选题：硅纳米线 + 碲薄膜　； 参考：《电子科技大学》2017年硕士论文

【摘要】：硅纳米线具有优于体硅和非晶硅材料的光学和电学特性,如高的陷光效应、载流子收集效率、量子限域效应和带隙可调等优点,因而在光电器件领域具有广泛的应用价值。本文首次使用射频磁控溅射法成功地在ITO玻璃上制备出硅纳米线(SiNWs),通过控制生长温度、Ar/H2及沉积时间实现了对硅纳米线的直径、长度与密度的可控生长。系统地研究了生长温度和Ar/H2对硅纳米线的表面形貌、内部晶体结构、光学和电学特性的影响。此外,在硅纳米线的基础上制备了碲/硅纳米线(Te/SiNWs)结构,研究了Te/SiNWs结构的微观结构、光学和电学性能,并得到以下结论:1,SEM图表明SiNWs的最佳生长温度和Ar/H2流量比分别为300℃和75/25。Raman图表明260℃时制备的SiNWs中纳米晶比例最大,300℃制备的SiNWs的短程有序性最高。FTIR谱表明SiNWs中不存在Si-H键,只存在少量的Si-H2键。SiNWs的吸收峰随衬温度和H2/Ar流量比的增加而先向紫外后向红外波段偏移。SiNWs的光学带隙分别在衬温为300℃和Ar/H2流量比为65/35时达到最大的1.89 eV和2.04 eV,其明暗电导率与衬温不成线性变化,与Ar/H2流量呈先增后减的趋势,明电导率在衬温为300℃时达到最大(10-4?-1cm-1)。I-V曲线表明SiNWs具有整流特性,整流值约为50 mA和-50 mA。2,室温下制备的Te薄膜连续性好,高于室温制备的Te膜表面形成了纳米结构。室温下制备的Te膜(不同厚度)均在中红外波段有高透射率(=67%)。Te/SiNWs结构的样品均在2150 nm出现明显的反射峰,而仅在100℃的制备温度下出现了570 nm和750 nm两处反射峰。Te/SiNWs结构样品的透射率均在中红外波段随波长同步增加,与制备温度呈先增后减的趋势,在可见-近红外波段,Te/SiNWs有低透射率(=17%)。在中红外波段,所有Te/SiNWs结构样品的吸收率均随波长的增加而减小,而在可见-近红外波段,Te/SiNWs吸收峰仅在制备温度为100℃时出现了两处。Te/SiNWs结构的I-V曲线同样表现出了整流特性。SEM和TEM图谱均表明:Te/SiNWs结构表面Te膜附着在SiNWs表面。XRD,Raman和HRTEM图均表明:附着在SiNWs表面的Te薄膜的内部晶体结构为多晶结构。
[Abstract]:Silicon nanowires have better optical and electrical properties than bulk silicon and amorphous silicon materials, such as high trapping effect, carrier collection efficiency, quantum limiting effect and tunable band gap, so they have wide application value in the field of optoelectronic devices. In this paper, Si nanowires have been successfully prepared on ITO glass by RF magnetron sputtering for the first time. The controllable growth of the diameter, length and density of Si nanowires has been achieved by controlling the growth temperature and the deposition time. The effects of growth temperature and Ar/H2 on the surface morphology, internal crystal structure, optical and electrical properties of silicon nanowires were systematically studied. In addition, the Te / SiNWs structure was prepared on the basis of silicon nanowires. The microstructure, optical and electrical properties of Te/SiNWs structure were studied. The following conclusions are obtained: the best growth temperature and Ar/H2 flow ratio of SiNWs are 300 鈩，

本文编号：1895597