CuS/TiO2纳米管异质结阵列的制备及光电性能

利用水热反应制备了CuS/TiO2纳米管异质结阵列,采用场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)和X射线衍射谱(XRD)等手段表征了异质结阵列的表面形貌和晶体结构.电流-电压曲线结果表明,CuS/TiO2纳米管异质结阵列具有明显的整流效应.根据表面光电压谱和相位谱,在376～600 nm之间,CuS/TiO2纳米管异质结阵列表现为p型半导体特征,电子在表面聚集;在300～376 nm之间表现为n型半导体特征,空穴在表面聚集;在376 nm处异质结阵列的表面光伏响应为零.CuS/TiO2和CuS/ITO之间界面电场的不同导致异质结在不同波长范围内表面电荷聚集的差异.光电化学性能测试发现,以CuS/TiO2纳米管异质结阵列为光阳极组成的光化学太阳电池,在大气质量AM 1.5G,100 mW/cm2标准光强作用下具有0.4%的光电转换能力.

Preparation and Photoelectrical Properties of CuS/TiO2 Nanotube Heterojunction Arrays

CuS/TiO2 nanotube heterojunction arrays were prepared by hydrothermal reaction. The surface morphology and crystalline phase of heterojunction arrays were characterized by field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM) and X-ray diffraction(XRD). The current-voltage curve of CuS/TiO2 nanotube heterojunction arrays reveals an obvious rectifying behavior. According to the results of surface photovoltage spectrum(SPS) and phase spectrum(PS), CuS/TiO2 nanotube heterojunction arrays show p-type semiconductor character and electrons aggregate at the surface in 376—600 nm, and n-type semiconductor character and holes aggregate at the surface in 300—376 nm. The surface photovoltage response is zero at 376 nm. The reason for difference aggregation properties in different wavelengths of heterojunction arrays is the competition result between interfacial electric filed of CuS/TiO2 and CuS/ITO. The photoelectrochemical property of CuS/TiO2 nanotube heterojunction arrays-base photoelectrochemical cell shows that 0.4% of photoelectricity conversion efficiency is achieved under 100 mW/cm2 simulated AM 1.5G sunlight.