GaAs纳米线阵列光阴极的制备及其特性研究

Preparation and characterization of GaAs nanowire array photocathode

采用改进的Stber法合成直径为500nm的SiO_2纳米球,用旋涂法将所合成的SiO_2纳米球制作掩模版,采用纳米球刻蚀法制备GaAs纳米线阵列。利用扫描电子显微镜(SEM)、漫反射谱对其进行了表征分析,再对所制备出的GaAs纳米线阵列结构进行Cs-F交替激活实验,使其表面形成负电子亲和势光阴极,并对最终制备出的GaAs纳米线阵列光阴极样品进行量子效率测试,验证了GaAs纳米线阵列结构的量子效率比GaAs基片提高50%以上,从而证实了纳米线阵列结构的高光电转换效率。

SiO_2 nanospheres with a diameter of 500 nm were synthesized by modified Stber method.The synthesized SiO_2 nanospheres were made as a mask layer by spin coating to prepare GaAs nanowire arrays through SiO_2 nanospheres mask.GaAs nanowire arrays were characterized and analyzed by using scanning electronic microscopy（SEM）and diffuse reflection spectra.After that,the Cesium-Fluoride（Cs-F）alternating activation experiment was conducted in order to form a negative electron affinity cathode on the surface of GaAs nanowire arrays.Finally,the quantum efficiency of as preparation GaAs nanowire array was measured.The results show that the quantum efficiency of GaAs nanowire arrays is more than 50% higher than that of GaAs substrate and confirm the high photoelectric conversion efficiency of nanowire arrays.