Graphene photodetector employing double slot structure with enhanced responsivity and large bandwidth
采用双槽结构具有更高的响应度和更大的带宽的石墨烯光电探测器
応答性と広帯域幅を増強したダブルスロット構造を用いたグラフェンフォトディテクタ
이중 슬롯 구조의 그래핀 광전 탐지기를 사용하여 더욱 높은 응답도와 넓은 대역폭을 가지고 있다
El Fotodetector de Grafeno con estructura de doble ranura tiene mayor respuesta y mayor ancho de banda
Photodétecteur de Graphène à double fente avec une plus grande réactivité et une plus grande largeur de bande
двухслойная структура графитовых фотодетекторов, с более высокой чувствительностью и более широкой полосой пропускания
¹ DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, Kgs. Lyngby DK-2800, Denmark
² School of Optical and Electrical Information and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
中国 武汉 华中科技大学光学与电子信息学院 武汉光电国家实验室
Silicon photonics integrated with graphene provides a promising solution to realize integrated photodetectors operating at the communication window thanks to graphene’s ultrafast response and compatibility with CMOS fabrication process. However, current hybrid graphene/silicon photodetectors suffer from low responsivity due to the weak light-graphene interaction. Plasmonic structures have been explored to enhance the responsivity, but the intrinsic metallic Ohmic absorption of the plasmonic mode limits its performance.
In this work, by combining the silicon slot and the plasmonic slot waveguide, we demonstrate a novel double slot structure supporting high-performance photodetection, taking advantages of both silicon photonics and plasmonics. With the optimized structural parameters, the double slot structure significantly promotes graphene absorption while maintaining low metallic absorption within the double slot waveguide.
Based on the double slot structure, the demonstrated photodetector holds a high responsivity of 603.92 mA/W and a large bandwidth of 78 GHz. The high-performance photodetector provides a competitive solution for the silicon photodetector. Moreover, the double slot structure could be beneficial to a broader range of hybrid two-dimensional material/silicon devices to achieve stronger light-matter interaction with lower metallic absorption.
