硅纳米线的制备及其光电性能

Preparation and Photoelectric Properties of Silicon Si NWs

采用金属辅助化学刻蚀的方法制备了作为光电阴极的纳米硅线,探索了纳米硅线的最佳生长条件。SEM表明所制备的纳米硅线具有典型的纳米阵列结构,反射率测试表明其可见光反射率在2%以下。纳米硅线光电阴极的光电化学分解水测试结果表明,由于所制备的硅纳米线阵列对光生载流子的产生和分离能力的提高,以及纳米结构带来的能带变化和电极/电解液界面处能带的改变,可见光下电解水时外加电压的开启电势正移了145 mV。

The silicon nanowires （SiNWs） array was used as the photo-electrode, which was fabricated by MACE （metal-assited chemical etching）. The typical nanometer array structure in SiNWs was observed by SEM. The optical reflectivity of SiNWs was under 2%. Because of the enhanced ability of generating and separating photogenerated carriers, as well as the energy gap changed in the interface of electrode/electrolyte, the onset potential exhibited 145 mV anodic shifted in the SiNWs array compared with the planar silicon.