Gold-patched graphene nano-stripes for high-responsivity and ultrafast photodetection from the visible to infrared regime

Abstract

Graphene is a very attractive material for broadband photodetection in hyperspectral imaging and sensing systems. However, its potential use has been hindered by tradeoffs between the responsivity, bandwidth, and operation speed of existing graphene photodetectors. Here, we present engineered photoconductive nanostructures based on gold-patched graphene nano-stripes, which enable simultaneous broadband and ultrafast photodetection with high responsivity. These nanostructures merge the advantages of broadband optical absorption, ultrafast photocarrier transport, and carrier multiplication within graphene nano-stripes with the ultrafast transport of photocarriers to gold patches before recombination. Through this approach, high-responsivity operation is realized without the use of bandwidth-limiting and speed-limiting quantum dots, defect states, or tunneling barriers. We demonstrate high-responsivity photodetection from the visible to infrared regime (0.6 A/W at 0.8 μm and 11.5 A/W at 20 μm), with operation speeds exceeding 50 GHz. Our results demonstrate improvement of the response times by more than seven orders of magnitude and an increase in bandwidths of one order of magnitude compared to those of higher-responsivity graphene photodetectors based on quantum dots and tunneling barriers.

Polariton Photonics Using Structured Metals and 2D Materials

“…As a result, nonzero net photocurrent can be generated without applying bias voltage, solving the dark current problem. In 2018, S. Cakmakyapan et al demonstrated a graphene photodetector with high responsivity over a wide wavelength regime (0.6 A W −1 at 0.8 µm and 11.5 A W −1 at 20 µm), setting a record of the widest photodetection bandwidth with high responsivity up to date . The structure is shown in figures on the left of Figure a, in which the metal electrodes are designed so that the incident light can be concentrated in the graphene channels within a broad spectrum from 0.8 to 20 µm, shown in the top right panel of Figure a.…”

“…b) Fast and high‐sensitivity gas identification by graphene molecule sensor. a) Reproduced with permission . Copyright 2018, Springer Nature.…”

“…In 2018, S. Cakmakyapan et al demonstrated a graphene photodetector with high responsivity over a wide wavelength regime (0.6 A W −1 at 0.8 μm and 11.5 A W −1 at 20 μm), setting a record of the widest photodetection bandwidth with high responsivity up to date. [155] The structure is shown in figures on the left of Figure 9a, in which the metal electrodes are designed so that the incident light can be concentrated in the graphene channels within a broad spectrum from 0.8 to 20 μm, shown in the top right panel of Figure 9a. Although the optical absorption is much lower at the short wavelength regime, which corresponds to interband transition, the high responsivity is still maintained at this regime, shown in the bottom two panels in Figure 9a.…”

“…a) Reproduced with permission. [155] Copyright 2018, Springer Nature. b) Reproduced with permission.…”

Mixing Properties of Room Temperature Patch‐Antenna Receivers in a Mid‐Infrared (λ ≈ 9 µm) Heterodyne System

“…However, they are limited by material nonuniformity, significant 1/f noise, and intrinsic low‐speed response. Recently, 2D material photodetectors have attracted a lot of attention, but they are not yet at the state of the art and moreover far from presenting a mature and reproducible fabrication process . Quantum well infrared photodetectors (QWIPs) based on GaAs/AlGaAs heterostructures have a competitive background‐limited detectivity (10 10 cm Hz 1/2 W −1 ) and a very high‐frequency response up to 100 GHz, due to their intrinsic short carrier lifetime (few ps) .…”