CdS量子点与金电极之间的光生电子交换.pdf

物理化学学报(Wuli Huaxue Xuebao) 2814 Acta Phys. -Chim. Sin . 2011, 27 (12), 2814-2820 December [Article] doi: 10.3866/PKU.WHX CdS 量子点与金电极之间的光生电子交换 岳 钊* 张 维 王 程 刘国华 牛文成 (南开大学电子系, 天津300071) 摘要: 对光照下CdS 量子点与金电极之间的光生电子交换过程进行了系统研究. 首先, 对基于电子隧穿的多 个光生电子转移过程进行了理论分析, 并进行了数学模型推导. 其次, 利用推导的数学模型在不同参数的条件 下进行了仿真研究. 最后, 测量了CdS 量子点修饰的金电极在不同偏置电压、不同光强和不同氧化物及还原物 浓度的条件下产生的光电流, 并将实验、理论及仿真结果三者相结合进行了分析讨论. 实验结果与仿真结果都 证明了理论模型的正确性. 关键词: 量子点; 电子隧穿; 光生电子交换; 光电流; 光电化学 中图分类号: O649 Photoinduced Electron Transfer between CdS Quantum Dots and Gold Electrodes YUE Zhao* ZHANG Wei WANG Cheng LIU Guo-Hua NIU Wen-Cheng (Department of Electronics, Nankai University, Tianjin 300071, P. R. China) Abstract: For a better design of quantum dots (QDs) based photoelectrochemical sensors, photoinduced electron transfer between CdS QDs and gold electrodes was studied. First, a theoretical study and mathematical model are given wherein several electron tunneling processes compete with each other to give a photocurrent under illumination. Second, simulations with different parameters were carried out. Finally, photocurrents from CdS QDs modified gold electrodes with dithiol groups were measured under different conditions. The results show that the amplitudes and directions of the photocurrents are affected by the applied potential, the light intensity, and the concentrations of oxidants and reducers. The experim