周期性硅纳米线和纳米多孔硅的制备及其光电性能研究

发布时间：2018-05-07 20:01

本文选题：纳米球光刻 + 纳米多孔硅　；参考：《上海师范大学》2016年硕士论文

【摘要】：纳米晶体硅材料如硅纳米线、硅纳米锥、纳米多孔硅等,相比于传统的体硅材料,因其独特的光电性质,已成为目前光电材料的研究热点。本论文以二维胶体球为模板对晶体硅硅片表面进行图形化,分别利用反应离子刻蚀与金属-辅助化学刻蚀方法,制备了纳米多孔硅与硅纳米线材料。系统地研究了影响二维聚苯乙烯胶体球(PS)自组装的实验条件,并在硅片表面制备了大面积紧密排列的胶体球模板。本论文的主要工作和结果如下:(1)以乙醇为分散介质,利用溶剂蒸发法自组装PS纳米球。通过改变基片表面性质、粒径大小、乙醇比例等条件,得出单层胶体晶体球模板制备条件。对于浓度2.5wt%的PS水分散剂,直径500 nm与1000 nm的PS中分散剂乙醇的最佳比例分别是50%与45%。确定RIE的最佳射频功率是40W。(2)系统地研究了晶体硅与刻蚀气体的反应过程,发现SF6气体是刻蚀硅基底的主要刻蚀剂;O_2气体是刻蚀稀释气体,同时也起到了侧壁保护的作用。射频功率越大,气体产生自由基的密度越大,刻蚀速率越快,但是刻蚀方向性变差。解决纳米线团簇问题的关键是将结构的高宽比控制在70以下,优化后的刻蚀速度为60 nm/s。(3)纳米多孔硅的反射谱实验实测数据与模拟计算结果证实,纳米多孔硅的周期常数决定了反射谱的最小值。相比于平面硅,硅纳米线与纳米多孔硅均具有优良的广谱减反特性。两种硅纳米结构在超过硅的光学带隙(1.12 e V)的波段内的反射率均低于6%。(4)在制备的周期性硅纳米线表面通过包覆Ti O_2、加载纳米金颗粒、沉积非晶硅等表面改性手段可以进一步提高硅纳米线的光电性能。
[Abstract]:Compared with traditional bulk silicon materials, nanocrystalline silicon materials, such as silicon nanowires, silicon nanometers and nano-porous silicon, have become the research focus of optoelectronic materials because of their unique photoelectric properties. In this paper, the surface of silicon wafer was graphically fabricated using two-dimensional colloidal spheres as template, and nanocrystalline porous silicon and silicon nanowires were prepared by reactive ion etching and metal-assisted chemical etching, respectively. The experimental conditions affecting the self-assembly of 2-D polystyrene colloidal spheres (PSs) were systematically studied, and a large area tightly arranged template of colloidal spheres was prepared on the surface of silicon wafers. The main work and results of this thesis are as follows: (1) using ethanol as dispersing medium, PS nanospheres were self-assembled by solvent evaporation. The preparation conditions of monolayer colloidal crystal sphere template were obtained by changing the substrate surface properties, particle size and ethanol ratio. For the concentration of 2.5 wt% PS aqueous dispersant, the optimum ratio of ethanol in PS with diameter of 500nm and 1000 nm is 50% and 45%, respectively. The optimum RF power of RIE is 40 W. / 2) the reaction process between crystalline silicon and etching gas is systematically studied. It is found that the gas of SF6 is the main etching agent for etching silicon substrate, and that the gas of O _ 2 is the etching dilution gas, and it also plays the role of side wall protection. The higher the RF power, the higher the density of free radical produced by the gas, the faster the etching rate, but the worse the etching direction is. The key to solve the problem of nanowire cluster is to control the aspect ratio of the structure below 70, and the optimized etching rate is 60 nm / s 路s. 3) the measured data of reflection spectrum of nano-porous silicon and the simulation results are proved. The periodic constant of nano-porous silicon determines the minimum value of reflection spectrum. Compared with planar silicon, silicon nanowires and nano-porous silicon have excellent broad-spectrum antireflection properties. The reflectivity of the two kinds of silicon nanostructures in the band beyond the optical band gap of silicon 1.12 EV) is lower than that of 60.40%) the surface of the prepared periodic silicon nanowires is coated with TIO _ 2, and the gold nanoparticles are loaded on the surface of the prepared silicon nanowires. Surface modification such as deposition of amorphous silicon can further improve the photoelectric properties of silicon nanowires.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB383.1

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