State Key Laboratory of Optoelectronic Materials and Technologies, Nanotechnology Research Center, School of Materials Science and Engineering, Sun Yat-sen University , Guangzhou 510275, Guangdong, People's Republic of China.
Nano Lett. 2017 Aug 9;17(8):4793-4800. doi: 10.1021/acs.nanolett.7b01566. Epub 2017 Jul 11.
Electrically tunable devices in nanophotonics offer an exciting opportunity to combine electrical and optical functions, opening up their applications in active photonic devices. Silicon as a kind of high refractive index dielectric material has shown comparable performances with plasmonic nanostructures in tailoring and modulating the electromagnetic waves. However, there are few studies on electrically tunable silicon nanoantennas. Here, for the first time we realize the spectral tailoring of an individual silicon nanoparticle in the visible range through changing the applied voltage. We observe that the plasmon-dielectric hybrid resonant peaks experience blue shift and obvious intensity attenuation with increasing the bias voltages from 0 to 1.5 V. A physical model has been established to explain how the applied voltage influences the carrier concentration and how carrier concentration modifies the permittivity of silicon and then the final scattering spectra. Our findings pave a new approach to build excellent tunable nanoantennas or other nanophotonics devices where the optical responses can be purposely controlled by electrical signals.
在纳米光子学中，电可调器件提供了一个令人兴奋的机会，可以将电和光功能结合起来，从而将其应用于主动光子器件中。硅作为一种高折射率介电材料，在调整和调制电磁波方面表现出与等离子体纳米结构相当的性能。然而，关于电可调硅纳米天线的研究很少。在这里，我们首次通过改变施加的电压，在可见光范围内实现了单个硅纳米粒子的光谱调整。我们观察到，随着偏置电压从 0 到 1.5V 的增加，等离子体-介电混合共振峰经历蓝移和明显的强度衰减。已经建立了一个物理模型来解释施加的电压如何影响载流子浓度，以及载流子浓度如何改变硅的介电常数，从而最终改变散射光谱。我们的发现为构建出色的可调谐纳米天线或其他纳米光子学器件开辟了一条新途径，这些器件的光学响应可以通过电信号进行有目的地控制。
