Fiona Beck Small Particles Big Hopes Absorption Enhancement

Fiona Beck Small Particles, Big Hopes: Absorption Enhancement in Silicon using Metallic Nanoparticles

Centre for Super Ear -saving Science

Regular Superhero Solar Energy Superheros

% Absorption Spectra of Silicon Rubbish absorption above 1000 nm Wavelength (nm)

Texturing to trap light in bulk silicon cells light SEM image of textured silicon taken by Luke Johnson

Localised Surface Plasmons in Metal Nanoparticles E-field -------e -e Incident Light ++++++ -e -e ++++++ ------- Time t + /2 c

Interface effects Silver Nanoparticle Dielectric layer Incident light Induced surface plasmon Light coupled into silicon in trapped modes

Sample Fabrication: 1) Silicon wafer, thin and shiny Oxidation for Si. O 2 2) Dielectric film deposition ~30 nm APCVD Ti. O 2 3) Silver film evaporation ~10 nm 4) Low temperature anneal ~260 degree C Nanoparticles !

Smallest particles Resonance peaks Biggest particles

Optical measurements Particles on front Light source Particles on rear Si. O 2 Coating Ti. O 2 Coating

Absorption Spectra for Particles on Silicon

Absorption Spectra for Particles on Silicon 16 fold increase in light absorption for particles on Ti. O 2 at 1150 nm 5. 6 times more absorption of light at 1150 nm for particles on the rear of a silicon-Si. O 2 sample

SEM Images Particles on Ti. O 2 Particles on Si. O 2

My supervisors Klaus Weber and Kylie Catchpole, currently at the Institute of Atomic and Molecular Physics in the Netherlands. Luke Johnson for the Ti. O 2 deposition and the nice SEM image and everyone who has helped me out in the labs.