摘要
The noble metal nanoparticles, such as gold, silver and copper, has been widely incorporated into the photoelectronic devices acting as a light-harvesting an- tenna and enhancing photocurrents through their light scattering or localized surface plasmon resonance effects. Here, this article presented the investigations into the use of gold nanocrystals to realize the plasmon-enhanced photocurrent generation in TiO2 nanorod-based quantum dots-sensitized solar cells （QDSSCs）. By introducing the gold nanocrystals, the short-circuit current density （Jsc） of QDSSCs was enhanced more than 10 % from 7.788 to 8.574 mA/cm^2 due to the direct injection of hot electrons from the gold nanocrystals to the photoanode. In order to confirm such conclusion, composite Au/TiO2 nanostructure was also fabricated. Indeed, the hot electrons injection resulted photocurrent density of ～5 mA/cm^2 was clearly observed under the visible light irradiation.
近年来,金、银、铜等金属纳米颗粒被广泛应用在光电器件中,这些金属颗粒自身特有的光散射效应或等离子共振效应可以用来增强光电器件中的光电流,但较少有研究能够在一维纳米线阵列体系中直接观察到这种光电流产生和增强的现象.本文通过水热反应制备了TiO2纳米棒阵列,通过柠檬酸钠还原HAuCl4 3H2O的方法制备了直径约20 nm的金纳米晶.为研究金纳米晶在量子点敏化太阳能电池中的光电流增强效应,构筑了ZnS/CdSe/CdS/TiO2核-壳结构的纳米线阵列化光阳极.在该量子点敏化太阳能电池体系中,通过简单地引入金纳米晶,短路电流从7.788 mA/cm2增加到8.574 mA/cm2,增强了约10%;整个器件的光电转换效率从1.66%增加到1.73%,增强了约4.2%.这种增强效应主要来源于金纳米晶受到激发后电子向ZnS/CdSe/CdS/TiO2光阳极注入所导致.为进一步证实该结论,通过原位反应使所制备的金纳米晶与TiO2纳米棒阵列复合,构筑了单一的Au/TiO2复合体系,在可见光照射下,清楚地观察到了光电流产生现象;而单一的TiO2在可见光照射下,并不能产生光电流.
基金
supported by the Program for Changjiang Scholars and Innovative Research Team in University(PCS IRT1126)
the National Natural Science Foundation of China(11274093,61376061 and 61240053)
