中红外波段硅波导集成二维材料光电探测器

The mid-infrared silicon waveguide-integrated photodetectors have important applications in the areas including lidar, sensing, and next generation communications, etc. While the traditional mid-infrared photodetection materials are not applicable for these photodetectors due to the large integration complexity or limited operation wavelength bands, the two dimensional (2D) materials such as graphene and black phosphorus (BP) enable flexible integration and wide band photodetection，and then provide a solution. However, there remain some problems in 2D material photodetectors’ overall performances including responsivities, sensivities, and bandwidths. To solve these problems, this project is going to focus on the study of mid-infrared silicon waveguide-integrated two dimensional material photodetectors, and the following three subjects will be included. (1) Research of mid-infrared silicon-2D material hybrid waveguide. (2) Modeling and design of novel devices. (3) Fabrication, measurement, and characterization of novel devices. The applicant has proposed an innovative structure based on thin silicon slot ridge waveguide and Bragg reflector to realize light-2D materials interaction enhancement and internal quantum efficiency improvement. A novel short channel BP photodetector has also been proposed to significantly reduce the carrier transport time. With these novel designs, the project is expected to realize graphene photodetectors with low bias voltages (<0.1V), high responsivities (200 mA/W), and high bandwidths (100 GHz), as well as BP photodetectors with high responsivities (>300 mA/W), high bandwidths (20 GHz), and low dark current (<1μA).

中红外（2-5 μm）硅波导集成光电探测器在激光雷达、传感和下一代光通信等领域有重要应用，但传统中红外探测材料因集成工艺复杂或波段受限等问题难以应用，具有集成灵活、覆盖波段广等优势的石墨烯、黑磷等二维材料提供了解决方案，但相关器件的响应度、灵敏度和带宽等综合性能还不足。为解决上述问题，项目拟围绕“中红外波段硅波导集成二维材料光电探测器”的主题，开展以下研究：1）中红外硅-二维材料混合光波导研究；（2）新型器件建模及设计；（3）器件工艺制备及测试表征。申请人提出集成布拉格反射器的薄硅狭缝脊波导创新结构实现光-二维材料作用增强和器件内量子效率提升，并提出新型短沟道黑磷探测器以缩短载流子渡越时间。本项目有望实现具备低偏置压（<0.1V）、高响应度（200 mA/W）和高带宽（100GHz）的石墨烯探测器和具备高响应度（300 mA/W）、高带宽（20 GHz）和低暗电流（<1μA）的黑磷探测器。

中红外（2-5 μm）硅波导集成光电探测器在激光雷达、传感和下一代光通信等领域有重要应用，但传统中红外探测材料因集成工艺复杂或波段受限等问题难以应用，具有集成灵活、覆盖波段广等优势的石墨烯、黑磷等二维材料提供了解决方案，但相关器件的响应度、灵敏度和带宽等综合性能还不足。为解决上述问题，项目拟围绕“中红外波段硅波导集成二维材料光电探测器”的主题，开展以下研究：1）中红外硅-二维材料混合光波导研究；（2）新型器件建模及设计；（3）器件工艺制备及测试表征。本项目实现了基于光电导/辐射热效应机制的高响应度高速金属-石墨烯-金属光电探测器，阐明了石墨烯-金属界面光电响应机制，制备了首个报道带宽达到20 GHz以上的2 μm硅基集成二维材料光电探测器。研制了基于p-n结结构的石墨烯光电探测器，零偏压测试带宽大于40 GHz，达到国际先进水平，进一步演示了器件与波分复用微环阵列的集成。研制了波导集成硅-石墨烯异质结光电探测器，首次提出并实现了工艺友好型石墨烯-硅-石墨烯异质结探测器，实现了优良综合性能：高线性动态范围(>20 dB)、高速（~30 GHz）和高光暗电流比(10^6 W^-1)，同时基于异质结能带分析阐明了石墨烯-硅界面光电响应机制。项目团队研制了薄硅等离子波导集成黑磷光电探测器，首次实现兼具高雪崩增益和GHz带宽特性的二维材料光电探测器。此外，项目团队开发100 nm薄硅波导平台，实现了高性能全刻蚀1.55 /2 μm波段耦合光栅和波长（解）复用器，提出基于维度调控的先进无源器件逆向设计方法等，相关成果有力支持了探测器的集成化研究。本项目通过综合性能优化以及集成化研究有力促进了硅基集成二维材料光电探测器的应用化发展。