High-performance graphene photodetector using interfacial gating

Abstract

Graphene based photo-detecting has received great attentions and the performance of such detector is stretching to both ends of high sensitivity and ultra-fast response. However, limited by the current photo-gating mechanism, the price for achieving ultra-high sensitivity is sacrificing the response time. Detecting weak signal within short response time is crucial especially in applications such as optical positioning, remote sensing, and biomedical imaging. In this work, we bridge the gap between ultra-fast response and ultra-high sensitivity by employing a graphene/SiO 2 /lightly-doped-Si architecture with revolutionary interfacial gating mechanism. Such device is capable to detect < 1 nW signal (with responsivity of ~1000 A W -1 ) and the spectral response extends from visible to near-infrared. More importantly, the photoresponse time of our device has been pushed to ~400 ns. The current device structure does not need complicated fabrication process and is fully compatible with the silicon technology. This work will not only open up a route to graphene-based high performance optoelectronic devices, but also have great potential in ultra-fast weak signal detection.

High-Performance Graphene-Based Electrostatic Field Sensor

“…No noticeable electrostatic responses are observed in the above two devices, which suggest that the interfacial amplification does play an important role in our electrostatic sensor. The functionality of the trap states to the gate effect has been verified in the photodetection device employing similar device architecture to our sensor 21 . To further certify the interfacial gain effect of the graphene/SiO 2 /Si system, we test the photodetection performance of our device (Supplementary Information Figure S2).…”

“…The electrostatic response can be reversed in sign and can even be switched off electrically by tuning the gate. Such phenomenon is due to the change of the type of conducting carrier in graphene from hole to electron and its number also changes with applied top gate voltage 21 . Furthermore, the linear dependence of the electrostatic response on bias under different static field is also shown in Fig.…”

Multicolor Broadband and Fast Photodetector Based on InGaAs–Insulator–Graphene Hybrid Heterostructure

“…Such a positive shift means that an additional negative gate photovoltage is generated at the InGaAs/SiO 2 interface under illumination. A higher positive gate bias is thus needed to offset the negative photovoltage and maintain charge neutrality, which is called the photogating effect 24,25. As illustrated in Figure 2c, energy band bending often occurs at the heterointerface to form a potential well, for example, the graphene/SiO 2 /InGaAs used in this work, because of the large amount of charges present in the oxide and the work function difference between the materials.…”

Design strategies for two‐dimensional material photodetectors to enhance device performance

“…Gan et al fabircated a waveguide‐integrated graphene photodetector which exhibits high responsivity with broad spectral bandwidth . Moreover, an interfacial gating mechanism was realized in graphene photodetector by Guo et al There are also other effective and prominent methods for promoting performance of 2D materials photodetectors.…”