Increasing organic solar cell efficiency with polymer interlayers

We demonstrate how organic solar cell efficiency can be increased
by introducing a pure polymer interlayer between the PEDOT:PSS
layer and the polymer: fullerene blend. We observe an increase in
device efficiency with three different material systems over a
number of devices. Using both electrical characterization and
numerical modeling we show that the increase in efficiency is
caused by optical absorption in the pure polymer layer and hence
efficient charge separation at the polymer bulkheterojunction
interface.