Student research opportunities
Plasmonic silicon infra-red photodetector
Project Code: CECS_898
This project is available at the following levels:
Engn4200, Engn R&D, Honours, Masters
Keywords:
Surface plasmons Plasmonics Photonics Semiconductors
Supervisor:
Dr Tom WhiteOutline:
The aim of this project is to develop a novel silicon photodetector capable of detecting sub-bandgap light at telecommunication wavelengths of 1300nm and 1550nm. This could replace expensive InGaAs detectors in some telecom applications and would be much easier to integrate into silicon-based photonic chips.
Conventional silicon photodetectors can only detect photons with energies higher than the silicon bandgap (ie wavelengths <1100nm), where silicon is absorbing. This project will focus on an alternative detector geometry where the light is absorbed in a thin nanostructured metal film on the surface of the silicon, and the resulting electrons are injected into the silicon to produce a current. This requires careful design of the metallic film to strongly absorb light at the correct wavelength while maximizing the electron injection efficiency and detector sensitivity. In particular, we will investigate the use of recently-developed plasmonic perfect absorber materials to achieve the strong wavelength-selective light absorption in very thin metal films.
Goals of this project
Model the theoretical sensitivity of metal-semiconductor photodetectors under different operating conditions
Design thin nanostructured metal films to strongly absorb light at telcommunications wavelengths
Design a photodetector combining metal nanostructures with silicon waveguides to create an integrated photodetector and model the optical and electrical response.
(If time) Fabricate the photodetector and measure its response.
Requirements/Prerequisites
Strong background in semiconductor physics and/or optics/photonics
Experience with Matlab, Mathematica or other programming software.
Student Gain
Research experience in an advanced photonics topic
In-depth understanding of photodetector operation and design
Optical and semiconductor modelling experience
Understanding of nanofabrication processes
Background Literature
Background reading can be provided on request
