Department of Chemistry, University of California, Berkeley, California 94720, United States.
Nano Lett. 2011 Dec 14;11(12):5189-95. doi: 10.1021/nl2023806. Epub 2011 Nov 21.
In recent photovoltaic research, nanomaterials have offered two new approaches for trapping light within solar cells to increase their absorption: nanostructuring the absorbing semiconductor and using metallic nanostructures to couple light into the absorbing layer. This work combines these two approaches by decorating a single-nanowire silicon solar cell with an octahedral silver nanocrystal. Wavelength-dependent photocurrent measurements and finite-difference time domain simulations show that increases in photocurrent arise at wavelengths corresponding to the nanocrystal's surface plasmon resonances, while decreases occur at wavelengths corresponding to optical resonances of the nanowire. Scanning photocurrent mapping with submicrometer spatial resolution experimentally confirms that changes in the device's photocurrent come from the silver nanocrystal. These results demonstrate that understanding the interactions between nanoscale absorbers and plasmonic nanostructures is essential to optimizing the efficiency of nanostructured solar cells.
在最近的光伏研究中，纳米材料为捕获太阳能电池内的光以增加其吸收率提供了两种新方法：对吸收半导体进行纳米结构化，以及使用金属纳米结构将光耦合到吸收层中。这项工作通过用八面体银纳米晶体修饰单纳米线硅太阳能电池，将这两种方法结合在一起。波长相关的光电流测量和有限差分时域模拟表明，光电流的增加出现在与纳米晶体表面等离子体共振相对应的波长处，而在与纳米线光学共振相对应的波长处则出现减少。具有亚微米空间分辨率的扫描光电流映射实验证实，器件光电流的变化来自银纳米晶体。这些结果表明，理解纳米级吸收体与等离子体纳米结构之间的相互作用对于优化纳米结构太阳能电池的效率至关重要。
