Ultra-Thin All-Epitaxial Plasmonic Detectors

TL;DR

This paper introduces an ultra-thin, all-epitaxial plasmonic infrared detector that uses surface plasmon-polariton modes for high efficiency at non-cryogenic temperatures, offering a scalable solution for mid-infrared applications.

Contribution

It presents a novel all-epitaxial device architecture combining plasmonic metals with quantum-engineered detectors in III-V semiconductors, enabling sub-diffractive absorption layers.

Findings

Achieves high external quantum efficiency at 195 K

Operates with a detector thickness of approximately λ₀/33

Outperforms existing commercial mid-infrared detectors

Abstract

We present an infrared photodetector leveraging an all-epitaxial device architecture consisting of a 'designer' plasmonic metal integrated with a quantum-engineered detector structure, all in a mature III-V semiconductor material system. Incident light is coupled into surface plasmon-polariton modes at the detector/'designer' metal interface, and the strong confinement of these modes allows for a sub-diffractive ($\sim \lambda_0 / 33$) detector absorber layer thickness, effectively decoupling the detector's absorption efficiency and dark current. We demonstrate high-performance detectors operating at non-cryogenic temperatures (T = 195 K), without sacrificing external quantum efficiency, and superior to well established and commercially-available detectors. This work provides a practical and scalable plasmonic optoelectronic device architecture with real world mid-infrared applications.