不同制备条件对硅纳米线的形貌和反射率影响

利用两步法-金属辅助化学刻蚀法(metal-assisted chemical etching, MACE)制备硅纳米线(silicon nanowires,SINWs)样品。研究了刻蚀温度、刻蚀时间、过氧化氢(H_2O_2)浓度对样品SINWs的形貌和反射率影响。研究发现,随着刻蚀时间增加, SINWs样品的长度随之增加,而反射率降低。H_2O_2浓度提高, SINWs样品的长度也增加,在浓度为0.1 mol/L时反射率降至最低。刻蚀温度升高, SINWs样品的长度先增加,然后随着SINWs生长速率变快的同时样品的形貌结构遭到破坏,反射率呈总体上升趋势。实验结果表明,改变制备过程中的反应条件,对SINWs的形貌会具有较大影响,同时SINWs阵列的反射率也会改变。SINWs的反射率强烈依赖于SINWs的长度、规整程度和空隙率大小等。

The Effect of Different Preparation Conditions on the Morphology and Reflectance of Silicon Nanowires

Silicon nanowires (SINWs) samples were prepared using a two-step process-metal assisted chemical etching (MACE). The effects of etching temperature, etching time and hydrogen peroxide (H₂O₂) concentration on the morphology and reflectivity of the SINWs are investigated. It can been found that the length of the SINWs increases with rising etching time, but the reflectance decreases. In addition, the length of the SINWs sample also increases as the H₂O₂ concentration increases. The reflectance is minimized at the H₂O₂ concentration of 0.1 mol/L. At the beginning, the length of the SINWs increases with increasing the etching temperature. Then the morphology of the sample is destroyed with increasing the etching temperature because of the uncontrollable and random growth of the SINWs. The reflectance generally increases. The results show that the morphology of SINWs would and the reflectivity of the SINWs also change with changing the reaction conditions of the process. The reflectance of SINWs is strongly dependent on the length, uniformity and void ratio of SINWs.