Interfacial Charge Transfer and Colloidal Semiconductor Dye-Sensitization: Mechanism Assessment via Stark Emission Spectroscopy

Abstract

Stark emission spectroscopy has been used to assess the nature of light-induced charge-injection processes occurring at molecular-dye/colloidal-semiconductor interfaces. Experiments reveal that eosin Y injects via a locally excited (LE) state. Coumarin-343 conceivably may react via an interfacial charge transfer state, although a simpler explanation centering on an environmentally perturbed LE state also is consistent with the experimental evidence.