Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.
Science. 2011 May 6;332(6030):702-4. doi: 10.1126/science.1203056.
Nanoantennas are key optical components for light harvesting; photodiodes convert light into a current of electrons for photodetection. We show that these two distinct, independent functions can be combined into the same structure. Photons coupled into a metallic nanoantenna excite resonant plasmons, which decay into energetic, "hot" electrons injected over a potential barrier at the nanoantenna-semiconductor interface, resulting in a photocurrent. This dual-function structure is a highly compact, wavelength-resonant, and polarization-specific light detector, with a spectral response extending to energies well below the semiconductor band edge.
纳米天线是用于光捕获的关键光学元件；光电二极管将光转换为电子电流以进行光电检测。我们表明，这两个截然不同、独立的功能可以组合到同一个结构中。耦合到金属纳米天线的光子激发共振等离子体，这些等离子体衰变成在纳米天线-半导体界面处的势垒上注入的高能“热”电子，从而产生光电流。这种双功能结构是一种高度紧凑、波长共振且偏振特定的光探测器，其光谱响应可扩展到远低于半导体能带边缘的能量。
