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

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 approach yields remarkable device performance featuring room temperature high sensitivity (NEP of 82 pW$$/\sqrt{{\bf{Hz}}}$$ / 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 very good 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.

Recent Advances in 2D Materials for Photodetectors

“…Very recently, Castilla et al. [ 106 ] innovatively employed a novel method by combining plasmonic antenna and hyperbolic phonon‐polaritons in hexagonal‐BN to effectively improve the performance of graphene‐based mid‐IR photodetector. The photodetector exhibits excellent properties such as high responsivity (27 mA W −1 ), noise‐equivalent‐power (82 pW/), and the response time reduced to 17 ns.…”

Hot carriers in graphene – fundamentals and applications

“…19a) have been used to compensate for the mismatch between the large area of the incoming radiation and the small photoactive area of the detector. 55,264,[273][274][275][276][277] At GHz frequencies, microwave resonators (see Fig. 19b) have been used to couple light with 99% efficiency to graphene bolometers.…”

“…Several of these sensitivity-enhancement strategies have been combined, in order to create high-performance long-wavelength photodetectors that operate at room-temperature. In the mid-IR region, where light absorption in graphene is particularly low due to Pauli blocking, Castilla et al 264 reported a PTE photodetectors based on clean a hBN-encapsulated graphene p–n junction with a responsivity of ∼27 mA W −1 (see Fig. 19c ), an NEP of ∼80 pW Hz −0.5 and a fast rise time 17 ns.…”

Probing nanoparticle substrate interactions with synchrotron infrared nanospectroscopy: Coupling gold nanorod Fabry-Pérot resonances with SiO2 and h−BN phonons

“…Characterizing these properties with simultaneously high spatial and spectral resolution is difficult but essential for the rational design of advanced materials with novel functionalities [10][11][12][13][14]. Today, a number of studies have made progress in this direction through a variety of near-field imaging and spectroscopy techniques [15][16][17][18][19][20][21][22][23], yet considerable work still lies ahead to better understand material design principles and characterization methods in the IR spectral regime.…”