Flame synthesis of plasmonic Au nanoparticles for enhanced photoactivity in photoelectrochemical solar cells

Elijah Thimsen (1), Scott Warren (1), Florian Le Formal (1), Leo-Philipp Heiniger and Michael Graetzel (1)

(1) Ecole Polytechnique Fédérale de Lausanne

     Abstract Number: 420
     Last modified: May 12, 2010

Abstract
Noble metal nanoparticles immobilized on substrates exhibit collective oscillations in their electron density known as surface plasmons when illuminated with photons at the resonance frequency. The surface plasmon produces a strongly enhanced electromagnetic field in the vicinity of the nanoparticle surface, which for certain geometries can be several orders of magnitude higher than the incident field. This enhanced field can be used to promote light absorption in the photoactive components of solar cells. The field enhancement is a strong function of particle size and spacing, making control over these parameters critical for synthesis processes. Synthesis of Au nanoparticles immobilized on substrates with controlled size and spacing via a flame aerosol reactor will be discussed. The relationship of the plasmon resonance frequency and inter-particle spacing to the performance enhancement in photoelectrochemical water splitting devices based on hematite iron oxide and photovoltaic dye sensitized solar cells will be presented.