TitleTowards low temperature sintering methods for dye sensitized solar cells
NameMurali, Sukanya (author), BIRNIE III, DUNBAR P (chair), Mann, Adrian (internal member), Du Pasquier, Aurelien (internal member), Atanassova, Paolina (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectMaterials Science and Engineering,
Dye-sensitized solar cells
DescriptionAccess to economically viable renewable energy sources is essential for the development of a globally sustainable society. Solar energy has a large potential to satisfy the future need for renewable energy sources. Dye sensitized solar cells are a third generation of photovoltaic technologies with the potential for low cost environmentally safe energy production. Commercialization of this technology requires that dye sensitized solar cells with higher efficiencies can be fabricated on flexible substrates. The commonly used material for the anode in a Dye Sensitized Solar Cell consists of titanium dioxide nanoparticles covered with a layer of light sensitizing dye. For efficient electron transport throughout the nanoparticle network, good particle interconnections are necessary. For low temperature processing these interconnections can be achieved through a hydrothermal process. The focus of this research is to understand at a fundamental level this reaction-based sintering process. A titanium alkoxide precursor was mixed with commercial titania nanoparticles and coated on a transparent conductive oxide substrate. The product of the hydrolysis and condensation of the alkoxide served to connect the nanoparticles thus improving the electrical conduction of the titania electrode; this was confirmed by solar cell testing and electrochemical impedance spectroscopy. To further understand the formation of interconnections during reactive sintering, a model system based on inert silica particles was investigated. Titanium alkoxide precursor was mixed with commercial silica particles and reacted. Three different types of silica particles were used: each with a different morphology. The silica-titania multilayers/powders were characterized using SEM, XRD and BET. The efficiency of DSSCs is higher when larger non-porous silica particles are used and thin nanocrystalline titania is coated on this superstructure. This gave insight into the locations where the reactive liquid finally goes as these reactions are carried out. As a further extension of this study, thin layers of this same kind of silica-titania composite were obtained by spin coating a titanium alkoxide sol mixed with monosized 500nm silica particles. SEM was used to examine the morphology of the contact/neck formation. Image analysis was done to quantify the effect of key process parameters on the average neck width at 2-particle contact points. The use of image analysis to study mixed oxide sub-monolayers in this way is the first of its kind. These observational tools and the model system approach developed in this research could be applied to many systems that are of interest for optical and mechanical applications.
NoteIncludes bibliographical references
Noteby Sukanya Murali
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.