Prosiectau Ffiseg ar gyfer myfyrwyr bl.3 a bl.4

Disgrifiad prosiect

Surface enhanced Raman spectroscopy

(supervisor: Rachel Cross)

Nature of project: experimental, data analysis

Available to students on full-time physics degree schemes or joint students.

Project description and methodology

Raman spectroscopy is a laser-based optical technique that probes vibrational states in molecules, liquids and solids. Its application to thin films is often limited by sensitivity and many approaches have been developed to enhance the Raman scattering from dilute systems. One method is to use nano-structured or low dimensional materials that demonstrate strong surface plasmon resonance effects that can result in increases of many orders of magnitude in the measured signals. This project will involve the measurement of Raman scattering in organic molecules in solution and in solid films with view to identifying all the observed vibrational modes with reference to the molecular symmetry. Standard SERS substrates and metal nano-particles, fabricated using chemical methods, will be used to quantify and explain the enhancement of the Raman signal for dilute systems.

A successful project will develop beyond the above in one/some of the following directions:
The project could be developed to investigate the effect of interference enhancement of Raman scattering in silicon oxide thin films on single crystal silicon substrates.

There is scope to model the process theoretically, comparing existing experimental data to literature and theory.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

Additional scope or challenge if taken as a Year-4 project: The 4th year version of this project will focus on organic molecules used in medical therapy and the determination of optimal SERS substrates and measurement parameters for their screening. It could also involve the application of complementary experimental methods such as atomic force microscopy and the development of theoretical models

Please speak to Rachel Cross if you consider doing this project.

Initial literature for students:

  1. Introduction to infrared and Raman spectroscopy, Norman B. Colthup (Primo)
  2. Principles of Surface-Enhanced Raman Spectroscopy and related plasmonic effects, Eric Le Ru Pablo Etchegoin (Primo)
  3. Raman Spectroscopy and its Application in Nanostructures, Shu-Lin, Zhang Zhang (Primo)

Novelty, degree of difficulty and amount of assistance required

The project is medium to high difficulty and will require training on spectrometer use and chemical preparation methods.

Project milestones and deliverables (including timescale)

milestoneto be completed by
Training on spectrometer end of October
First measurements of bulk materialChristmas
Measurement of thin films on standard substratesend of February
Fabrication and measurement on nanoparticlesEaster

Students taking this project will have to submit a full risk assessment form