In English

Fabrication and Characterization of Plasmonic Nanostructures for Solar Cells

Carl Wadell
Göteborg : Chalmers tekniska högskola, 2010. 70 s.
[Examensarbete på avancerad nivå]

The objective of this work is to produce titanium dioxide covered gold nanoparticles. These particles are to be used to enhance the performance of dye-sensitized solar cells. Apart from its normal role as an electron acceptor in these types of solar cells, the titanium dioxide shell is here used to protect the gold nanoparticles against etching by the I−/I−3 electrolyte used in these solar cells. Two different methods to produce these core/shell nanoparticles were investigated. The first method use heat assisted diffusion of titanium to the surface of samples containing a mixture of gold and titanium. XPS measurements show that annealing of films containing gold and titanium in an oxygen environment increase the surface concentration of titanium. However, a complete layer of titanium dioxide could not be achieved, at least not for reasonably long annealing times. In addition, it is found that upon annealing sandwiched samples of gold and titanium (Au/Ti/Au) at certain conditions gold crystallites form on the surface of the samples. The second method is to fabricate gold nanoparticles using hole-mask colloidal lithography and then adding the titanium dioxide shell using a chemical deposition method called successive ionic layer adsorption and reaction (SILAR). This method was found capable of producing titanium dioxide films on the samples. It was also found that the growth rate of the deposited titanium dioxide film is higher on gold compared to that on glass. Tests on the chemical and thermal stability of the nanostructures were conducted by studying the changes of the plasmon resonance of the particles using spectrophotometry. They reveal that it is possible to protect the gold nanoparticles against etching by a I−/I−3 electrolyte using the SILAR method. It was also found that the titanium dioxide shells can protect the gold nanoparticles against shape changes upon annealing.

Nyckelord: nanofabrication, gold nanoparticles, titanium dioxide, plasmon resonance, hole-mask colloidal lithography, SILAR, dye-sensitized solar cells



Publikationen registrerades 2010-12-16. Den ändrades senast 2015-02-11

CPL ID: 131074

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