Free-space graphene/silicon photodetectors operating at 2 micron

TL;DR

This paper reports on the development and characterization of graphene/silicon photodetectors operating at 2 microns, demonstrating promising responsivity for free-space optical applications at room temperature.

Contribution

It introduces a novel design and fabrication of graphene/silicon photodetectors functioning at 2 microns, with detailed characterization and performance analysis.

Findings

Responsivity of 10.3 mA/W internally and 0.16 mA/W externally

Interfacial trap density measured at 1.1x10^14 eV^-1cm^-2

Device performance aligns with theoretical predictions

Abstract

This paper presents the design, the fabrication and the characterization of Schottky graphene/silicon photodetectors, operating at both 2 micron and room temperature. The graphene/silicon junction has been carefully: characterized device shows a non ideal behaviour with the increasing temperature and the interfacial trap density has been measured as 1.1x10^14 eV^-1cm^-2. Photodetectors are characterized by an internal (external) responsivity of 10.3 mA/W (0.16 mA/W) in an excellent agreement with the theory. Our devices pave the way for developing hybrid graphene-Si free-space illuminated PDs operating at 2 micron, for free-space optical communications, optical coherence tomography and light-radars.