Dear Ken,

When the absorber layer in Organic Solar Cell (OSC) is thick enough, the absorbed

light from the TCO-side generates carriers in the absorber bulk,

often far from the electric field and close to the front contact and

they are hard to reach the junction area near the Absorber/Buffer region.

Therefore, side-illuminated superstrate solar cells require more

attention towards the carriers recombination near the TCO contact in order to improve the collection. The Short-circuit current

density (Jsc) has a strong dependence on the thickness of the

absorber layer.

Good luck.

Thank you fro your reply! Isn't that all also true for the standard device architecture? What makes the inverted device different?

Dear Ken Johnson,

It is not alwayd true that inverted organic cells typically have lower efficiencies than the standard architecture. It very much depends on the device structure and layer thickness. The inverted device structure of solution processed OPVs is very often limited by the layer by layer deposition due to incompatible to the processing even if good energy alignment for some cases. This problem can be solved by vacuum deposition instead of solution processed layer. There are some publications involved this published by the group of Prof Martin Heeney. Their inverted OPVs have higher efficiency than normal structures which I witnessed their device testing.