Highly efficient UV detection in a metal-semiconductor-metal detector with epigraphene

TL;DR

This paper demonstrates that epitaxial graphene on silicon carbide can be used to create highly efficient, self-powered UV detectors with record-high detectivity and quantum efficiency, suitable for practical sensor arrays.

Contribution

The study introduces a new high-performance UV detector based on epigraphene MSM devices with record efficiency and ease of fabrication, advancing UV sensor technology.

Findings

Peak external quantum efficiency of ~85% for 250-280 nm wavelengths

Responsivity of 134 mA/W enabling self-powered operation

Record high specific detectivity of 3.5 x 10^15 Jones

Abstract

We show that epitaxial graphene on silicon carbide (epigraphene) grown at high temperatures (T > 1850 {\deg}C) readily acts as material for implementing solar-blind ultraviolet (UV) detectors with outstanding performance. We present centimeter-sized epigraphene metal-semiconductor-metal (MSM) detectors with peak external quantum efficiency of ~ 85% for wavelengths 250-280 nm, corresponding to nearly 100% internal quantum efficiency when accounting for reflection losses. Zero bias operation is possible in asymmetric devices, with the responsivity to UV remaining as high as R = 134 mA/W, making this a self-powered detector. The low dark currents Io ~50 fA translate into an estimated record high specific detectivity D = 3.5 x 10^15 Jones. The performance that we demonstrate, together with material reproducibility, renders epigraphene technologically attractive to implement high-performance planar MSM devices with a low processing effort, including multi-pixel UV sensor arrays, suitable for a number of practical applications.