This thesis explores the production, characterization, and water oxidation efficiency of wide bandgap semiconductors made through femtosecond-laser irradiation of various
materials. Our investigation focuses on three main aspects: 1) producing titanium dioxide (TiO2) from titanium
metal, 2) using our laser-made materials in a photoelectrochemical cell for water oxidation, and 3) utilizing the femtosecond laser to create a variety of other mixed metal oxides for
further water oxidation studies and biological applications.
We first discuss producing TiO2 and titanium nitride. We report that there is chemical selectivity at play in the femtosecond laser doping process so not all dopants in the surrounding atmosphere will necessarily be incorporated. We then show that the material made from laser-irradiation
of titanium metal, when annealed, has a three-fold enhancement in overall water oxidation when irradiated with UV light. We attribute this enhancement through various material characterization methods to the creation of a more pure form of rutile
TiO2 with less defects. We then present a variety of studies done with doping both TiO2 and other oxides with broadband photoelectrochemistry and offer that the dopant incorporation hurts the overall water oxidation rate.
Lastly, we use the laser-treated titanium to test cell adhesion and viability. Our results demonstrate an ability to femtosecond-laser
process semiconductors to produce materials that no one has made previously and study their
properties using collaborations across chemistry and biology, yielding true interdisciplinary research.
| Identifer | oai:union.ndltd.org:harvard.edu/oai:dash.harvard.edu:1/14226078 |
| Date | 18 March 2015 |
| Creators | Phillips, Katherine Collett Furr |
| Contributors | Mazur, Eric |
| Publisher | Harvard University |
| Source Sets | Harvard University |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation, text |
| Format | application/pdf |
| Rights | open |
Page generated in 0.0019 seconds