Zero‐Bias Long‐Wave Infrared Nanoantenna‐Mediated Graphene Photodetector for Polarimetric and Spectroscopic Sensing

Abstract

Graphene has attracted great interest for integrated photonic platforms in the long‐wave infrared (LWIR) for spectroscopic and polarimetric sensing due to the capability of on‐chip integration, fast response, and broadband operation. However, graphene suffers from low photoresponsivity and thus poor sensing performance due to weak absorption. Polarization detection using graphene is hindered by its small in‐plane anisotropy. Here, nanoantenna‐mediated graphene photodetectors (NMGPDs) are proposed to enhance responsivity by tailoring the nanoantenna near‐field distribution to generate a strong photoresponse. The devices demonstrate a high responsivity of 6.3 V W−1 under zero bias at room temperature with low noise‐equivalent power of 1.6 nW Hz−1/2. Furthermore, polarization detection is enabled by artificial near‐field anisotropy enabled by double L‐shaped nanoantennas. The proposed LWIR NMGPDs achieve subtle polarization‐angle detection down to 0.05° thanks to the unusual negative polarization ratio of −1. To demonstrate the advances of LWIR NMGPDs for molecule detection, acetone is chosen as an analyte for spectroscopic sensing. The devices show a low limit of detection of 115 ppm, and fast dynamic gas sensing response of 6 s for real‐time monitoring. These results reveal the potential of the device as a multi‐functional on‐chip miniaturized optoelectronic platform for polarimetric and spectroscopic sensing toward real‐time environmental monitoring and biomedical screening.

Polarization‐ and Gate‐Tunable Optoelectronic Reverse in 2D Semimetal/Semiconductor Photovoltaic Heterostructure

“…The phenomenon of infinite PR values is similar to the recently reported nanoantennamediated semimetal photodetectors where the PR values can cover a wide range (1→∞/-∞→−1) by tuning the antennas orientation. [24,54,55] To further confirm the polarization-induced reverse in polarized photocurrent, the time-dependent dynamic photoresponse by varying the polarization angles at V G of -12 V and V DS of 0 V is shown in Figure 5h and Figure S21 (Supporting Information). It is clearly observed that the photocurrent varies with angles and has a sign reversal from positive to negative.…”

Low-dimensional van der Waals materials for linear-polarization-sensitive photodetection: materials, polarizing strategies and applications

“…In addition, as the symmetry of the optical antennas increases, the anisotropy of the photovoltage weakens, consolidating that the BPVE is caused by the asymmetry of the optical antennas. Following this success, most recently, Xie et al have constructed a self-driven long-wave infrared photodetector by modifying double L-shaped Au nanoantennas onto a graphene channel [258]. Impressively, the hybrid device manifests distinct polarized-resolved photovoltage and demonstrates a sensitive noise-equivalent polarization-angle perturbation down to 0.05 • .…”

Graphene-based nanotechnology in the Internet of Things: a mini review

“…Graphene's high electrical conductivity enhances the performance of IoT communication systems, enabling faster and more reliable data transmission. A graphene-based nano-antenna is a tiny antenna structure made from graphene [ 48 ] which can operate across a wide range of frequencies, including terahertz [ 49 , 50 ], due to graphene's tunable conductivity. At the nanoscale, their size facilitates precise signal control and manipulation of light and electromagnetic waves, while graphene's high electrical conductivity minimizes signal losses and maximizes efficient radiation, culminating in enhanced signal reception and transmission.…”