High-Responsivity Graphene鈥揃oron Nitride Photodetector and Autocorrelator in a Silicon Photonic Integrated Circuit

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• 作者：Ren-Jye Shiue ; Yuanda Gao ; Yifei Wang ; Cheng Peng ; Alexander D. Robertson ; Dmitri K. Efetov ; Solomon Assefa ; Frank H. L. Koppens ; James Hone ; Dirk Englund
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：November 11, 2015
• 年：2015
• 卷：15
• 期：11
• 页码：7288-7293
• 全文大小：396K
• ISSN：1530-6992

文摘

Graphene and other two-dimensional (2D) materials have emerged as promising materials for broadband and ultrafast photodetection and optical modulation. These optoelectronic capabilities can augment complementary metal鈥搊xide鈥搒emiconductor (CMOS) devices for high-speed and low-power optical interconnects. Here, we demonstrate an on-chip ultrafast photodetector based on a two-dimensional heterostructure consisting of high-quality graphene encapsulated in hexagonal boron nitride. Coupled to the optical mode of a silicon waveguide, this 2D heterostructure-based photodetector exhibits a maximum responsivity of 0.36 A/W and high-speed operation with a 3 dB cutoff at 42 GHz. From photocurrent measurements as a function of the top-gate and source-drain voltages, we conclude that the photoresponse is consistent with hot electron mediated effects. At moderate peak powers above 50 mW, we observe a saturating photocurrent consistent with the mechanisms of electron鈥損honon supercollision cooling. This nonlinear photoresponse enables optical on-chip autocorrelation measurements with picosecond-scale timing resolution and exceptionally low peak powers.