锯齿型硅纳米线的制备及其光电性能研究

发布时间：2019-05-21 13:00

【摘要】：硅纳米线(SiNWs)阵列结构具有独特的陷光性能,用作晶硅太阳电池表面减反射层能够有效的提高光的吸收率,为进一步提高光电转换效率奠定了基础。本文采用成本低廉且操作简单的金属催化化学刻蚀法(MCCE),通过交替刻蚀成功制备出形貌高度可控的锯齿型硅纳米线(ZSiNWs)阵列结构,并就不同参数对纳米线形貌的影响进行研究。在此基础上探讨了 ZSiNWs结构的减反射性能和少数载流子寿命,取得了一些有意义的成果。主要研究内容和结论如下:(1)在单个溶液刻蚀实验中,证明H202浓度主要影响刻蚀方向,即较低浓度下为各向异性刻蚀,较高浓度下为各向同性刻蚀,而HF浓度主要影响刻蚀速率;在相同HF浓度,不同H2O2浓度下的交替刻蚀实验中,验证了交替刻蚀法制备ZSiNWs的可能性,并证明无限制增大H2O2浓度差来制备ZSiNWs是不可行的。(2)在浓度为[HF]/[H2O2]=9.2M/0.04M 和[HF]/[H2O2]=2.3M/0.4M 的两种溶液中交替刻蚀,分别强化了各向异性刻蚀与各向同性刻蚀,使所得ZSiNWs形貌高度可控。系统研究了沉积时间、刻蚀时间与基底类型对纳米线形貌的影响,结果表明,沉积时间对纳米线形貌影响较大,沉积时间为40s和80s时纳米线较为均匀有序;刻蚀时间主要影响刻蚀深度;交替刻蚀法制备ZSiNWs适用于非(100)基底。(3)ZSiNWs阵列机构具有优异的减反射性能,在200-1100nm波段平均反射率低至6.6%。对比发现,沉积时间对其表面反射率影响较小,而随着刻蚀时间增长,表面反射率明显升高,最高至10.7%。(4)对沉积时间为40s条件下制备所得ZSiNWs分别进行了 Ⅰ键钝化,H键钝化和SiO2膜钝化实验,并测试了钝化前后结构的少子寿命。结果表明,三种钝化方法均使得少子寿命明显提高,但Ⅰ键钝化与H键钝化衰减较快,只有SiO2膜钝化具有较高的稳定性。总体而言,钝化效果为SiO2膜钝化H键钝化I键钝化。
[Abstract]:The (SiNWs) array structure of silicon nanowires has unique trapping properties. As an antireflective layer on the surface of silicon solar cells, it can effectively improve the absorptivity of light, which lays a foundation for further improving the photoelectric conversion efficiency. In this paper, a highly controllable sawtooth silicon nanowire (ZSiNWs) array structure was successfully fabricated by alternating etching of (MCCE), a metal catalytic chemical etching method with low cost and simple operation. The effects of different parameters on the morphology of nanowires were studied. On this basis, the antireflection performance and minority carrier lifetime of ZSiNWs structure are discussed, and some meaningful results are obtained. The main research contents and conclusions are as follows: (1) in the experiment of single solution etch, it is proved that the concentration of H202 mainly affects the direction of etch, that is, it is anisotropy etch at lower concentration and isotropic etch at higher concentration. The concentration of HF mainly affects the etch rate. In the experiment of alternating etching at the same HF concentration and different H2O2 concentration, the possibility of preparing ZSiNWs by alternating etch method was verified. It is proved that it is not feasible to prepare ZSiNWs by increasing the concentration difference of H2O2 without restriction. (2) alternately etched in two solutions with concentrations of [HF] / [H2O2] = 9.2M/0.04M and [HF] / [H2O2] = 2.3M/0.4M. Anisotropy etch and isotropic etch are strengthened respectively, so that the morphology of ZSiNWs is highly controllable. The effects of deposition time, etch time and substrate type on the morphology of nanowires were studied systematically. the results show that the deposition time has a great influence on the morphology of nanowires, and the nanowires are uniform and orderly when the deposition time is 40 s and 80 s. The etch time mainly affects the etch depth, and the alternating etch method is suitable for the preparation of ZSiNWs substrate. (3) the ZSiNWs array mechanism has excellent antireflection performance, and the average reflectivity in 200-1100nm band is as low as 6.6%. It is found that the deposition time has little effect on the surface reflectivity, but with the increase of etch time, the surface reflectivity increases obviously. The highest is 10.7%. (4) the I bond passivation, H bond passivation and SiO2 film passivation of ZSiNWs prepared under the condition of 40 s deposition time were carried out, and the minority carrier lifetime of the structure before and after passivation was tested. The results show that the minority carrier lifetime is obviously improved by the three passivation methods, but the decay of I bond passivation and H bond passivation is faster, and only SiO2 film passivation has high stability. Generally speaking, the passivation effect of SiO2 film is H bond passivation I bond passivation.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O613.72;TB383.1

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