Wavelength-dependent near-infrared microbolometer for short-wavelength infrared light with gold nanowire grating optical absorber
Wavelength-dependent near-infrared microbolometer for short-wavelength infrared light with gold nanowire grating optical absorber
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用于短波长红外光的波长相关近红外微测辐射热计，具有金纳米线光栅光吸收器
DOI：
10.1007/s00542-020-05004-3
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Yoshitada Isono
中科院分区：
文献类型：
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作者：
Tatsuya Tsubota;Akio Uesugi;Koji Sugano;Yoshitada Isono
近红外(NIR)成像已被用于各种领域的无损和非接触检测，如食品和药品检测以及医疗诊断。目前使用的短波红外光(SWIR)传感器由于其检测原理，需要一个珀尔帖制冷器和一个衍射光栅光谱仪。因此，实现低成本和小型化的SWIR成像设备仍然具有挑战性，并且在实际应用中存在局限性。在这项研究中，我们提出了一种利用绝缘体上硅(SOI)晶片制作的测辐射热计型探测器元件，作为一种低成本、小型化的SWIR图像传感器元件。我们采用了镀硅的金(Au)纳米线光栅结构作为波长相关的SWIR吸收材料，在不使用分光镜的情况下实现了波长选择性成像。利用微电子机械系统(MEMS)技术，在双固支硅梁上设计并制作了一种基于Au纳米线栅结构的器件。测量了器件的电学特性随器件温度和SWIR辐照强度的变化。结果表明，半导体的电阻温度系数为负，随着器件温度的升高和SWIR辐射强度(波长1530 nm)的增加，电阻呈线性下降。有限元分析和理论计算的结果显示出相似的趋势。在波长为1530-1565 nm的范围内，以5 nm为增量对其进行了电阻评估。根据吸收光谱证实了吸收体集成测辐射热计装置能够实现电阻对波长的响应。
Near-infrared (NIR) imaging has been used for nondestructive and non-contact inspections in various areas, such as food and medicine inspections and medical diagnoses. The short-wavelength infrared light (SWIR) sensor currently used requires a Peltier cooler and a diffraction grating spectroscope owing to its detection principle. Thus, realizing a low-cost and miniaturized SWIR imaging device remains challenging and has limitations for practical applications. In this study, we propose a bolometer-type detector element fabricated using a silicon-on-insulator (SOI) wafer as a low cost and miniaturized SWIR image sensor element. We adopted gold (Au) nanowire grating structures coated with silicon as wavelength-dependent SWIR absorbers and aimed at wavelength-selectivity imaging without using a spectroscope. A device was designed and fabricated with Au nanowire grating structures on a doubly clamped Si beam using microelectromechanical system (MEMS)) technology. The electrical characteristics of the device were measured depending on device temperature and SWIR irradiation intensity. It was found that electrical resistance decreased linearly with increasing device temperature and SWIR irradiation intensity (wavelength at 1530 nm), as semiconductors have negative temperature coefficients of resistance. The results show similar trends from both finite element method (FEM) analysis and theoretical calculation. The resistances at wavelengths ranging from 1530 to 1565 nm at 5 nm increment were evaluated. It was confirmed that absorber-integrated bolometer device enabled wavelength-dependent response of the resistance according to the absorption spectrum.