Universal reconstructive polarimetry with graphene-metal infrared photodetectors

TL;DR

This paper introduces a scalable, graphene-based infrared photodetector capable of reconstructing light's intensity and polarization using gate-tuned responsivity, offering a versatile alternative to non-scalable van der Waals stacking methods.

Contribution

It demonstrates a universal, graphene-metal junction photodetector for reconstructive polarimetry, utilizing gate tuning to determine infrared power and polarization angle.

Findings

Successful polarization reconstruction with various device geometries.

Effective responsivity tuning across different graphene qualities.

Feasibility demonstrated with both encapsulated and CVD graphene.

Abstract

Recent advent of smart photodetectors, where in-situ tuning of responsivity enables the reconstruction of light intensity, polarization and spectrum by a single device, has revolutionized the field of optoelectronics. So far, most such reconstructive detectors were realized with non-scalable technology of van der Waals stacking. Here, we demonstrate the infrared reconstructive polarimetry with photodetectors based on conventional gated graphene-metal junctions. The reconstruction exploits the gate tuning of polarization contrast, which enables the determination of both infrared power and polarization angle from photovoltage measurements at two different gate voltages. The physics enabling the polarimetry lies in polarization-dependent shift of the electron hot spot near the contact, and the gate tuning of photosensitive barrier width. We further show the universality of polarization reconstruction, i.e. its feasibility with different geometries of the junction, and with graphene of different quality, from boron-nitride encapsulated flakes to the scalable chemical vapor deposited films.