The achievement of long-lived photoinduced redox separation lifetimes has long been a central goal of molecular-based solar energy conversion strategies. The longer the redox-separation lifetime, the more time available for useful work to be extracted from the absorbed photon energy. Here we describe a novel strategy for dye-sensitized solar energy applications in which redox-separated lifetimes on the order of milliseconds to seconds can be achieved based on a simple toolkit of molecular components. Specifically, molecular chromophores (C), electron acceptors (A) and electron donors (D) were self-assembled on the surfaces of mesoporous, transparent conducting indium tin oxide nanoparticle (nanoITO) electrodes to prepare both photoanode (nanoITO|–A–C–D) and photocathode (nanoITO|–D–C–A) assemblies. Nanosecond transient-absorption and steady-state photolysis measurements show that the electrodes function microscopically as molecular analogues of semiconductor p/n junctions. These results point to a new chemical strategy for dye-sensitized solar energy conversion based on molecular excited states and electron acceptors/donors on the surfaces of transparent conducting oxide nanoparticle electrodes.
Nature Chemistry (2016) doi:10.1038/nchem.2536
Received 23 November 2015 Accepted 26 April 2016 Published online 06 June 2016
http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2536.html