Spectroscopic and electrochemical characterization of dye-sensitized, multilayered, and molecular photovoltaic solar cells.

摘要

Independence from fossil fuel-based energy sources is necessary to continue to meet rapidly growing global energy demands. Although harnessing solar energy into a useable form has been a societal goal for centuries, the appeal of converting this abundant, renewable, and clean energy supply seems to be growing on a daily basis in the new millennium. In the following chapters, I will describe several projects that have been directed toward the goal of efficient solar energy conversion using unexplored cell designs and characterization methods.; Chapter 1 provides a historical introduction to solar energy conversion and introduces many of the basic concepts that define solar cell efficiencies. Modern solar cells are categorized as conventional or excitonic solar cells, and the unique operation of each category is explained. In the final pages of this chapter, common efficiency measurements are described.; Chapter 2 presents a photothermal spectroscopic approach to elucidating the energetics of efficiency-robbing surface electronic trap states in Gratzel-type solar cells. The data presented provide a glimpse into the wealth of information that can be obtained by this methodology.; Chapters 3 and 4 focus on multilayer sensitization of flat semiconductor surfaces with porous chromophoric films. Chapter 3 describes the assembly and characterization of multilayer films using zirconium phosphonate chemistry. This chapter is devoted to the spectroscopic and surface characterization of the assembled films. Chapter 4 continues the work on these films by characterizing their porosity using conventional and unconventional electrochemical techniques. After demonstrating that the assembled films are porous, solar cells are assembled with porous multilayer films and their efficiencies are measured.; Chapter 5 builds upon the successful assembly of porous films in the previous chapters to generate bulk heterojunction solar cells. The inherent porosity of these films is utilized to create bulk heterojunction solar cells that are interpenetrated on the molecular level.