The study of Ruthenium polypyridyl complexes for dye sensitized solar cell applications

Abstract

Nanocrystals are of great scientific interest as their properties form a bridge between bulk material properties and those of atomic or molecular structures. Researchers have been taking advantage of the unique properties of nanocrystals since the early 1990's to produce new device architectures for solar energy conversion and light-emitting diodes (LED). In order to limit our dependence on fossil fuels and provide an energy solution for the future, renewable energy research is currently a major area of focus. One such device is a dye-sensitized solar cell (DSSC) that makes use of ruthenium polypyridyl dyes. Ruthenium polypyridyl complexes and their direct applications to dye-sensitized solar cells will be studied. Chapter 2 examines the synthesis, separation, and characterization of linkage isomers of the well-studied diisothiocyanato ruthenium dye N3. Chapter 3 examines the synthesis of amino substituted ruthenium bipyridine complexes and how the HOMO and LUMO energy levels affect charge injection into the metal oxide. Chapter 4 uses ultrafast transient absorption (TA) spectroscopy in collaboration with the Blank research group to study the charge injection of a diethylamino-substituted ruthenium dye into a ZnO nanocrystal. A second device that will be studied is the light-emitting diode. Chapter 5 will focus on the synthesis and characterization of air-stable, monodisperse, highly photoluminescent indium phosphide (InP) nanocrystals, which emit from visible to infrared wavelengths. A wide range of particle sizes can be produced with narrow size distributions by changing the growth time or reaction concentrations. In addition, a successive ion layer adsorption and reaction (SILAR) technique is used to deposit a shell to stabilize the core against oxidation and increase the photoluminescence. The stability and emission are assessed using UV-Vis and fluorescence spectroscopy.