Plasmonic graphene photodetector based on channel photo-thermoelectric effect

TL;DR

This paper introduces a CMOS-compatible graphene plasmonic photodetector utilizing the photo-thermoelectric effect, achieving high responsivity at telecom wavelengths through efficient plasmonic coupling and thermal effects across a homogeneous graphene channel.

Contribution

It presents a novel on-chip graphene photodetector design that leverages plasmonic waveguides and the PTE effect for enhanced performance at telecom wavelengths.

Findings

Achieves electronic temperatures over 12000K with low input power

Responsivity exceeds 200 A/W at 1550 nm wavelength

Can isolate PTE photocurrent from other effects under certain conditions

Abstract

We propose an on-chip CMOS compatible graphene plasmonic photodetector based on the photo-thermoelectric effect (PTE) that occurs across an entire homogeneous graphene channel. The proposed photodetector incorporates the long-range dielectric-loaded surface plasmon polariton (LR-DLSPP) waveguide with a metal stripe serving simultaneously as a plasmon supporting metallic material and one of the metal electrodes. Large in-plane component of the transverse magnetic (TM) plasmonic mode can couple efficiently to the graphene causing large temperature increases across an entire graphene channel with a maximum located at the metal stripe edge. As a result, the electronic temperatures exceeding 12000K at input power of only a few tens of {\mu}W can be obtained at the telecom wavelength of 1550nm. Even with limitations such as the melting temperature of graphene (T= 4510 K), a responsivity exceeding at least 200 A/W is achievable at telecom wavelength of 1550 nm. It is also shown that under certain operation conditions, the PTE channel photocurrent can be isolated from photovoltaic and p-n junction PTE contributions providing an efficient way for optimizing the overall photodetector performance.