Transient optical studies of interfacial energetic disorder at nanostructured dye-sensitised inorganic/organic semiconductor heterojunctions.

Abstract

Broadening needs energy: Hole-transfer reactions at a dye-sensitised nanocrystalline TiO2/organic hole-conductor (HTM) interface are mainly driven by the free energy difference ΔG(dye-HTM). Inhomogeneous broadening of ΔG(dye-HTM) controls the yield of this interfacial charge-transfer reaction (see picture, curve b) and is therefore an important limitation on the voltage output of photovoltaic devices based upon such interfaces.