Highly Enhanced SWIR Image Sensors Based on Ge1-xSnx-Graphene Heterostructure Photodetector
Highly Enhanced SWIR Image Sensors Based on Ge1-xSnx-Graphene Heterostructure Photodetector
复制标题
基于Ge1-xSnx-石墨烯异质结构光电探测器的高度增强型短波红外图像传感器
DOI：
10.1021/acsphotonics.8b01731
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发表时间：
2019
期刊：
影响因子：
7
通讯作者：
Wang Qiming
中科院分区：
文献类型：
--
作者：
Yang Fan;Yu Kai;Cong Hui;Xue Chunlai;Cheng Buwen;Wang Nan;Zhou Lin;Liu Zhi;Wang Qiming
Ge1–xSnx 具有可调谐带隙，覆盖 1 至 2.6 μm 的全短波红外 (SWIR)，为硅基 SWIR 光电检测提供了一种新范例。然而，低吸收和高表面复合仍然是实现高性能光电探测器的很大限制。这项工作证明了具有高响应率、光电导增益和探测率的GeSn-石墨烯异质结构光电探测器可以有效减轻负担。与纯GeSn光电探测器相比，石墨烯的引入不仅有效解决了GeSn有源层表面态严重的问题，而且即使在相对较弱的光照下，光电流和响应速度也实现了大幅提升，这表明光生载流子可以以更高的效率分离和传输。同时，在周围环境中暴露4个月后，性能并未出现衰退。此外，将该异质结构集成到尺寸为440×440μm2的20×20像素探测器阵列中，通过掩模测量方法清晰地获得了字母“E”的图像。与CMOS技术的兼容性为此类光电探测器在短波红外光通信和成像、遥感和生物医学方面的应用提供了新的机会。
Ge1–xSnxwith a tunable bandgap that covers full shortwave infrared (SWIR) from 1 to 2.6 μm presents a new paradigm for silicon-based SWIR photodetection. However, low absorption and high surface recombination remain to be large limitations for realization of high performance photodetector. This work demonstrates GeSn–graphene heterostructure photodetectors with high responsivity, photoconductive gain, and detectivity can effectively lessen the burdens. Compared with the pure GeSn photodetector, the introduction of graphene not only effectively solves the problem of serious surface states of the GeSn active layer, but achieves large enhancements in both photocurrent and response speed, even under a relatively weak illumination, which indicates photogenerated carriers can be separated and transported in higher efficiency. At the same time, there is no recession in performance after a 4 month exposure in ambient environment. In addition, the heterostructure is integrated into a 20 × 20 pixel detector array with a size of 440 × 440 μm2and an image of letter “E” is clearly obtained according to a mask measurement method. The compatibility with CMOS technique offers such photodetector new opportunities for application in SWIR optical communication and imaging, remote sensing, and biomedical.