Stabilization Of Chromophores On High Surface Area Metal Oxide Semiconductor Surfaces By Atomic Layer Deposition

The stability of metal oxide bound chromophores and catalysts are important for the lifetime and ultimately the commercial viability of dye-sensitized solar cells (DSSCs) and dye-sensitized photoelectrosynthesis cells (DSPECSs). This is particularly true in water oxidation DSPECs where the surface-bound chromophores are known to be unstable under aqueous conditions and elevated pHs. The use of ALD for stabilizing the surface is the concern of this particular invention. Atomic Layer Deposition (ALD) of Al2O3 and other insulating oxides on the photoanodes of DSSCs is known to slow recombination between electrons in the semiconductor and the redox mediator which increases open circuit voltage (Voc) and improves device efficiency. While ALD has been used to bind metal oxides onto chromophores on the surface of a material; it has not been used as a blocking material until this invention. Dr. Parson\'s group has used ALD of Al2O3 onto the surface-bound chromophores demonstrating a 10X increase in surface stability which leads to increased performance during the lifetime of DSSCs and DSPECSs. This technique is potentially generalizable for other ALD materials and choromophores including: Al2O3 TiO2 SiO2 ZrO2 Fe2O3 MnO2 Co2O3 NiO In2O3 Mo2O5 SnO2 Ta2O5 HfO2 and SrTiO3. Patent Information: PCT filed