Credit: Fang et al. ©2016 American Chemical Society
Recent Study Demonstrates Innovative Enhanced Graphene Photodetector with Plasmonic Fractal Metasurface
Graphene is a very promising material for photo detection due to its unique properties, e.g. ultrabroadband optical absorption, ultrafast electron speed, and wavelength independent absorption. However, single layer graphene - with only single atom depth - exhibits very low optical absorption, which limits its application in photodetection systems.
A recent study by Jieran Fang et al, published in NanoLetters, demonstrates a new path forward for significant photo detection enhancement in graphene. In this paper, which was also highlighted in the February 2017 issue of the American Physical Society, researchers designed a gold fractal metasurface, similar in shape to a snowflake, and measured its electromagnetic character. As part of this study, a Nanonics MV2000 NSOM system was employed for plasmonic characterization of the snowflake metasurface with near field collection mode NSOM.
The obtained results demonstrated strong plasmonic generation near the branches and the edges of the fractal structure. It was demonstrated that the fractal metasurface integrated in graphene photodetector as source and drain provided enhancement factors of over 8-13. Additional advantages of this new enhanced graphene photodetector are broadband and polarization insensitive. This work indicates the great potential of enhanced graphene photodetectors in photodetection technology.