Organic Photodiodes with an Extended Responsivity using Ultrastrong Light-Matter Coupling

TL;DR

This paper introduces a novel organic photodiode design that uses polaritons in the ultra-strong coupling regime to extend responsivity into the near-infrared, achieving high efficiency and tunability beyond traditional exciton absorption limits.

Contribution

The work demonstrates polariton-based organic photodiodes operating in the ultra-strong coupling regime with tunable spectral response and improved quantum efficiency in the near-infrared range.

Findings

Operates in ultra-strong coupling regime at visible and infrared wavelengths

Achieves near-infrared responsivity beyond traditional exciton absorption

External quantum efficiencies surpass control devices

Abstract

In organic photodiodes (OPDs) light is absorbed by excitons, which dissociate to generate photocurrent. Here, we demonstrate a novel type of OPD in which light is absorbed by polaritons, hybrid light-matter states. We demonstrate polariton OPDs operating in the ultra-strong coupling regime at visible and infrared wavelengths. These devices can be engineered to show narrow responsivity with a very weak angle-dependence. More importantly, they can be tuned to operate in a spectral range outside that of the bare exciton absorption. Remarkably, we show that the responsivity of a polariton OPD can be pushed to near infrared wavelengths, where few organic absorbers are available, with external quantum efficiencies exceeding those of a control OPD.