沉积电量对CdTe/TiO2纳米管阵列同轴异质结的形成和光电性能影响研究

he highly ordered TiO2 nanotube arrays on pure titanium are prepared by using the two-step anodic oxidation method. The co-deposition potential of underpotential deposition (UPD) of Cd and Te elements on TiO2 nanotubes array substrate is determined by adjusting the ammonia concentration, and the thin film electrodes with CdTe/TiO2 nanotube arrays coaxial heterogeneous structure are successfully obtained. The crystalline structure, morphology, optical performance, photoelectric activity, and electrolchemical properties of samples with the coaxial heterogeneous structure that were fabricated using the three different deposition charge amounts are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrophotometry (EDX), ultraviolet-visible spectrophotometer (UV-Vis), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and other testing means. The results show that the CdTe/TiO2 nanotube array coaxial heterojunctions fabricated using 8C charge amount have highest photo absorption rate under the visible light, smallest barrier to overcome in the process of photoelectric response, and fastest photoinduced carrier mobility among the samples investigated. The as-prepared coaxial heterojunction sample exhibits a remarkable improved photoconversion efficiency of 7.64 % compared with that of the pure TiO2 nanotube substrate before sensitization (1.35 %).