Back contact dye-sensitized solar cells

Abstract The objective of this work was to develop back-contact dye-sensitized solar cells (back-contact DSCs). These solar cells comprise working and counter electrodes on the same side of the dye-sensitized TiO2 film, in either an interdigitated or a coplanar configuration. In the novel solar cell architectures, transparent conductive electrodes can be replaced by metal-based electrodes. This facilitates the use of cheaper and more conductive electrode materials in dye-sensitized solar cells. We presented in Chapter 1 an introduction to solar energy and solar cells including dye-sensitized solar cell, followed by a literature review on relevant research. In Chapter 2, we summarized experimental details, including materials, reagents, general DSC fabrication methods, and DSC characterization techniques. In Chapter 3, we described the first step in the fabrication of interdigitated back-contact DSCs (IBCDSCs) - the laser ablation process to produce interdigitated electrodes. Successfully patterned electrodes are essentially required to produced working IBCDSCs. In Chapter 4, we developed a pulsed-current electrochemical deposition method for producing Pt catalytic coatings in IBCDSCs. The method was found also suitable for platinizing counter electrodes for conventional DSCs. In Chapter 5 and chapter 6, we discussed the fabrication of interdigitated and coplanar back-contact DSCs (IBCDSCs and CBCDSCs). We achieved the highest conversion efficiencies of 3.6 % and 4.6 % on the two devices measured under simulated AM1.5G sunlight. All the results were compared to the performance of conventional DSCs using identical TiO2, dyes and electrolytes. In Chapter 7, we described three-terminal tandem DSCs comprising conventional TiO2 photoelectrodes and IBCDSCs. Nearly 10 % improvements in the photocurrent and conversion efficiencies were shown by using the IBCDSCs as back subcells. The final chapter drew general conclusions and proposed outlook of the future work for the present research.