Grating-Based Surface Plasmon Resonance Sensor for Visible Light Employing a Metal/Semiconductor Junction for Electrical Readout
Grating-Based Surface Plasmon Resonance Sensor for Visible Light Employing a Metal/Semiconductor Junction for Electrical Readout
复制标题
DOI：
10.1109/jsen.2022.3213760
复制
发表时间：
2022-12
影响因子：
4.3
通讯作者：
Ryota Kuroki;Shinichi Suzuki;S. Yasunaga;Masaaki Oshita;T. Kan
中科院分区：
文献类型：
--
作者：
Ryota Kuroki;Shinichi Suzuki;S. Yasunaga;Masaaki Oshita;T. Kan
在这项研究中，我们提出了一种与可见光耦合的电读出表面等离子体共振(SPR)化学传感器，以避免水的显著光吸收。采用严格耦合波分析(RCWA)方法，在n型硅(n-Si)衬底上采用纳米加工/微细加工方法制作了亚微米间距、高30 nm的金(Au)衍射栅。在Au/n-Si界面的肖特基势垒处，表面等离子体共振产生的超热电子被转化为光电流。根据器件的$I-V$特性估算出肖特基势垒高度为$Q{\Phi}_{\mathm{B}}=0.72$eV。当葡萄糖水溶液的浓度改变金栅的折射率时，光电流的峰位移符合SPR理论。假设入射波长和入射角度固定，噪声分析显示折射率分辨率为3.4-4.0×10-5美元。由于这种结构消除了SPR实验中笨重的光学元件，这将有助于实现薄型单芯片无标记化学传感器。
In this study, we proposed an electrical readout surface plasmon resonance (SPR) chemical sensor coupled with visible light to avoid significant light absorption of water. A gold (Au) diffraction grating with a submicrometer pitch, designed using the rigorous coupled-wave analysis (RCWA) method to have a submicrometer pitch and 30-nm-tall Au grating, was fabricated on an n-type silicon (n-Si) substrate by nanofabrication/microfabrication. The hot electrons generated by SPR on the grating are converted to photocurrent at the Schottky barrier at the Au/n-Si interface. The Schottky barrier height was estimated based on the $I-V$ characteristics of the device to be $q{\Phi}_{\mathrm{B}} = 0.72$ eV. The peak shift of photocurrent was observed to be consistentwith the SPR theory when the concentration of glucose aqueous solution changed the refractive index on the Au grating. Assuming that the incident wavelength and angle were fixed, a noise analysis revealed a refractive index resolution of $3.4-4.0 \times 10^{-5}$ refractive index unit (RIU). Since this structure eliminated bulky optics in SPR experiments, it would contribute to the realization of a thin single-chip label-free chemical sensor.