Electrochemical Scanning Tunneling Microscopy of Dye Sensitized Solar Cells

Photoelectrochemical cells provide a promising future for providing energy from the sun. Though bulk studies on PEC systems can suggest possible alternative materials and system designs, the fundamental knowledge of charge transport through a PEC required for the engineering and optimization of the cell calls for more intricate research in terms of spatial resolution to further explore the discrepancies and inefficiencies within the system. In one such attempt to provide detailed information on the functioning of a PEC system in terms of its electronic properties and its corresponding photocurrent generation, we have applied electrochemical scanning tunneling microscopy to the investigation of a dye sensitized solar cell. This system provides a measurement of photocurrent generation along the surface of the nanocrystalline metal oxide working electrode at nanoscale resolution through which electron/hole generation on the surface can be calculated. In this talk, we will compare the working nature of different materials such as nanowires, colloidal thin films and hybrid structures to understand the metal oxide/dye/electrolyte interface reactivity, improve the charge transfer of the electrons along the surface and provide better photon to electron conversion efficiency.