Analysis of Stacked-Photo-Anode for Photoelectrochemical Water Splitting Reaction

In photoelectrochemical water splitting, every impinging photon should not only be absorbed but also be utilized towards reaction. While increasing photoelectrode thickness in photoelectrochemical reactors facilitates photon absorption, it has a debilitating effect on efficiency if the thickness required for complete photon absorption is much more than the exciton diffusion length, which is a property determined by the material and its processing. To address this issue, we demonstrate a general experimental methodology with a stack of CdSe photoanodes wherein the thickness of each photoelectrode is of the order of exciton diffusion length and which improves overall photocurrent by about 50%.