Organic-thin-film-coated solar cells: Energy transfer between surface pyrene molecules and the silicon semiconductor substrate

The energy transfer processes in a pyrene thin film, deposited onto a silicon solar cell, are investigated. An increase in the solar cell efficiency is observed for cells coated with a pyrene thin film. The increase in efficiency is attributed to a combination of two effects: (i) the antireflective properties of the pyrene film and (ii) direct energy transfer from pyrene to silicon. A comparison of emission, photoexcitation and spectral response data reveals the nature of the pyrene energy transfer to be radiative.