Supermode hybridization: a material-independent route towards record Schottky detection sensitivity using <0.05 {\mu}m3 amorphous absorber volume

TL;DR

This paper introduces a material-independent hybridization technique that significantly enhances Schottky photodetector sensitivity by over 200 times, enabling high-performance detection in ultra-small amorphous absorber volumes.

Contribution

The study demonstrates a novel supermode hybridization approach that boosts guided-wave Schottky detection sensitivity without relying on crystalline materials.

Findings

Achieved record sensitivity of -55 dBm in amorphous-based detectors.

Enhanced light-matter interaction in nanostructures with absorber volume <0.05 μm³.

Demonstrated potential for improved photodetectors in integrated photonics.

Abstract

Schottky photodetectors are attractive for CMOS-compatible photonic integrated circuits, but the trade-off between photon absorption and hot carrier emission often compromises the detection fidelity and sensitivity. Here, we report a hybridization-based waveguiding effect that can improve the sensitivity of guided-wave Schottky detection by >200x. By hybridizing the supermodes guided by asymmetrical coupled plasmonic nanostructures, light-matter-interaction can be significantly enhanced even if the thickness of the light absorbing region is only a few nanometers, thus allowing the absorption and emission efficiencies to be simultaneously optimized for the first time. Using amorphous-based active junction with absorbing volume of only 0.031 {\mu}m3, our detectors demonstrate record experimental sensitivity of -55 dBm, approaching that of crystalline-based Ge counterparts with >36x larger absorption region. The ability to maximize field overlap within small device volume and improve photodetection fidelity without using crystalline materials pave the way towards improved back-end-of-line interconnection, single photon detection, and 2D optoelectronics.