Plasmonic antenna coupling to hyperbolic phonon-polaritons for sensitive and fast mid-infrared photodetection with graphene

TL;DR

This paper presents a novel graphene-based mid-infrared photodetector that uses plasmonic antenna coupling to hyperbolic phonon-polaritons in hexagonal-BN, achieving high sensitivity and fast response at room temperature.

Contribution

It introduces a new device architecture that efficiently couples plasmonic antennas with hyperbolic phonon-polaritons to enhance mid-infrared photodetection performance.

Findings

Achieved NEP of 82 pW/√Hz at room temperature

Fast rise time of 17 nanoseconds

Excellent agreement between model and experiment

Abstract

Integrating and manipulating the nano-optoelectronic properties of Van der Waals heterostructures can enable unprecedented platforms for photodetection and sensing. The main challenge of infrared photodetectors is to funnel the light into a small nanoscale active area and efficiently convert it into an electrical signal. Here, we overcome all of those challenges in one device, by efficient coupling of a plasmonic antenna to hyperbolic phonon-polaritons in hexagonal-BN to highly concentrate mid-infrared light into a graphene pn-junction. We balance the interplay of the absorption, electrical and thermal conductivity of graphene via the device geometry. This novel approach yields remarkable device performance featuring room temperature high sensitivity (NEP of 82 pW-per-square-root-Hz) and fast rise time of 17 nanoseconds (setup-limited), among others, hence achieving a combination currently not present in the state-of-the-art graphene and commercial mid-infrared detectors. We also develop a multiphysics model that shows excellent quantitative agreement with our experimental results and reveals the different contributions to our photoresponse, thus paving the way for further improvement of these types of photodetectors even beyond mid-infrared range.