Spatially controlled electrostatic doping in graphene p-i-n junction for hybrid silicon photodiode

Tiantian Li, Dun Mao, Nick W. Petrone, Robert Grassi, Hao Hu, Yunhong Ding, Zhihong Huang, Guo Qiang Lo, James C. Hone, Tony Low, Chee Wei Wong, Tingyi Gu*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

280 Downloads (Pure)


Sufficiently large depletion region for photocarrier generation and separation is a key factor for two-dimensional material optoelectronic devices, but only a few device configurations have been explored for a deterministic control over the space charge region area in graphene with convincing scalability. Here we investigate a graphene-silicon p-i-n photodiode defined in a foundry processed planar photonic crystal waveguide structure, achieving visible—near-infrared, zero-bias, and ultrafast photodetection. Graphene is electrically contacting to the wide intrinsic region of silicon and extended to the p an n doped region, functioning as the primary photocarrier conducting channel for electronic gain. Graphene significantly improves the device speed through ultrafast out-of-plane interfacial carrier transfer and the following in-plane built-in electric field assisted carrier collection. More than 50 dB converted signal-to-noise ratio at 40 GHz has been demonstrated under zero bias voltage, the quantum efficiency could be further amplified by hot carrier gain on graphene-i Si interface and avalanche process on graphene-doped Si interface. With the device architecture fully defined by nanomanufactured substrate, this work demonstrates post-fabrication-free two-dimensional material active silicon photonic devices.

Original languageEnglish
Article number36
JournalNpj 2d Materials and Applications
Issue number1
Publication statusPublished - 1 Dec 2018


Dive into the research topics of 'Spatially controlled electrostatic doping in graphene p-i-n junction for hybrid silicon photodiode'. Together they form a unique fingerprint.

Cite this