Ultra-high sensitivity infra-red detection and temperature effects in a graphene–tellurium nanowire binary hybrid

Abstract

The optoelectronic performance of hybrid devices from graphene and optically sensitive semiconductors exceeds conventional photodetectors due to a large in-built optical gain. Tellurium nanowire (TeNW), being a narrow direct band gap semiconductor (∼0.65 eV), is as an excellent potential candidate for near infra-red (NIR) detection. Here we demonstrate a new graphene-TeNW binary hybrid that exhibits a maximum photoresponsivity of ∼10 A W at 175 K in the NIR regime (920 nm-1720 nm), which exceeds the photoresponsivity of the most common NIR photodetectors. The resulting noise-equivalent power (NEP) is as low as 2 × 10 W Hz, and the specific detectivity (D*) exceeds 5 × 10 cm Hz W (Jones). The temperature range of optimal operation, which extends up to ≈220 K and ≈260 K for 1720 nm and 920 nm excitation, respectively, is primarily limited by the electrical conductivity of the TeNW layer, and can further be improved by lowering of the defect density as well as inter-wire electronic coupling.

Investigating photoresponsivity of graphene-silver hybrid nanomaterials in the ultraviolet

“…Details regarding mesh size and boundary conditions used in the simulations are given in the section titled "Experimental section." We model the total enhancement (|E|/|E 0 |) 2 max that refers to the squared ratio of magnitude of the local to incident electric field over the total volume of the unit cell. The total enhancement as a function of wavelength is plotted in Fig.…”

“…The spectrally flat, low intrinsic absorption of 2.3% in graphene 1 is large considering it is only an atom thick; however, it still is a limiting factor for optoelectronics, such as photodetection applications. Various schemes to enhance the interaction of light with graphene [2][3][4][5][6] have been implemented, of which integration with plasmonic nanoparticles is particularly attractive. [7][8][9][10] The subwavelength localization and enhancement of the electric field around the nanoparticles can lead to a higher responsivity at the plasmon resonance.…”

Number‐Resolved Single‐Photon Detection with Ultralow Noise van der Waals Hybrid

“…Determining the number of photons in an optical pulse with single‐photon resolution is the ultimate goal in photodetection . Planar hybrids of graphene and transition metal dichalcogenides (TMDC) are unique optoelectronic elements where coherent transfer of photogenerated electrons across the van der Waals interface results in extremely large gain at low feedback noise . In an ideal photon counting device, the signal‐to‐noise ratio (SNR) is limited by emission statistics of the optical source.…”

Low-Noise Mid-Infrared Photodetection in BP/h-BN/Graphene van der Waals Heterojunctions

“…Two-dimensional materials are emerging as promising mid-IR sensitive materials due to their broad bandgap coverage and flexible integrability [6,7,8]. These advantages provide new opportunities for material/circuit integration such that cryogenic operation of state-of-the-art mid-IR photodetectors is unnecessary [9,10]. Recently, black phosphorus (BP) was rediscovered as a promising material for mid-IR photonics.…”