6. State of the art in organic photovoltaics

As mentioned above, considering that a minimum of two materials with electron-donor and electron-acceptor characteristics must be mixed to form an effective active layer, a large number of different systems can be envisaged. We won't go into an exhaustive list here, but it's worth noting that there are different sub-classes of active layers, each offering a different approach to research. If we consider electron acceptors derived from fullerene as materials of the past, there are several categories still in contention, and therefore currently under development. As mentioned above, we can distinguish between binary and ternary layers, as well as polymeric materials and small molecules.

The published conversion record for a single-volume heterojunction test is very recent (it is regularly improved, sometimes several times a year, proof of the current momentum of this...