Terahertz photodetection in scalable single-layer-graphene and hexagonal boron nitride heterostructures

TL;DR

This paper demonstrates scalable, large-area graphene/hBN heterostructures for room-temperature terahertz photodetection, achieving fast response times and low noise, advancing integration of 2D materials in THz optoelectronics.

Contribution

It introduces a scalable method for THz detection using CVD-grown graphene integrated with hBN, maintaining high performance in a large-area heterostructure.

Findings

Response times ~5 ns achieved.

Noise equivalent power ~1 nW/Hz^1/2.

Effective thermoelectric detection in scalable heterostructures.

Abstract

The unique optoelectronic properties of single layer graphene (SLG) are ideal for the development of photonic devices across a broad range of frequencies, from X-rays to microwaves. In the terahertz (THz) range (0.1-10 THz frequency) this has led to the development of optical modulators, non-linear sources, and photodetectors, with state-of-the-art performances. A key challenge is the integration of SLG-based active elements with pre-existing technological platforms in a scalable way, while maintaining performance level unperturbed. Here, we report on the development of room temperature THz detection in large-area SLG, grown by chemical vapor deposition (CVD), integrated in antenna-coupled field effect transistors. We selectively activate the photo-thermoelectric detection dynamics, and we employ different dielectric configurations on SLG on Al2O3 with and without large-area CVD hBN capping to investigate their effect on SLG thermoelectric properties underpinning photodetection. With these scalable architectures, response times ~5ns and noise equivalent powers ~1nWHz-1/2 are achieved under zero-bias operation. This shows the feasibility of scalable, large-area, layered materials heterostructures for THz detection.