Masoudian Saadabad Reza, Pauly Christian, Herschbach Norbert, Neshev Dragomir N, Hattori Haroldo T, Miroshnichenko Andrey E
School of Engineering and Information Technology, University of New South Wales, Canberra, ACT 2600, Australia.
IEE S.A., Bissen L-7795, Luxembourg.
Nanomaterials (Basel). 2021 Feb 8;11(2):428. doi: 10.3390/nano11020428.
Fast detection of near-infrared (NIR) photons with high responsivity remains a challenge for photodetectors. Germanium (Ge) photodetectors are widely used for near-infrared wavelengths but suffer from a trade-off between the speed of photodetection and quantum efficiency (or responsivity). To realize a high-speed detector with high quantum efficiency, a small-sized photodetector efficiently absorbing light is required. In this paper, we suggest a realization of a dielectric metasurface made of an array of subwavelength germanium PIN photodetectors. Due to the subwavelength size of each pixel, a high-speed photodetector with a bandwidth of 65 GHz has been achieved. At the same time, high quantum efficiency for near-infrared illumination can be obtained by the engineering of optical resonant modes to localize optical energy inside the intrinsic Ge disks. Furthermore, small junction capacitance and the possibility of zero/low bias operation have been shown. Our results show that all-dielectric metasurfaces can improve the performance of photodetectors.
对于光电探测器而言，快速检测具有高响应度的近红外（NIR）光子仍然是一项挑战。锗（Ge）光电探测器广泛应用于近红外波长，但在光电探测速度和量子效率（或响应度）之间存在权衡。为了实现具有高量子效率的高速探测器，需要一种能有效吸收光的小型光电探测器。在本文中，我们提出了一种由亚波长锗PIN光电探测器阵列构成的介电超表面的实现方案。由于每个像素的亚波长尺寸，已实现了带宽为65 GHz的高速光电探测器。同时，通过设计光学谐振模式将光能局域在本征锗盘内部，可获得近红外照明下的高量子效率。此外，还展示了小的结电容以及零偏置/低偏置工作的可能性。我们的结果表明，全介质超表面可以提高光电探测器的性能。
