P-type dye-sensitized solar cells
We are developing p-type systems in order to construct tandem DSCs which have a photoactive cathode and anode.
Sensitizer (D) is photoexcited by light.
Electrons are transfered from the excited state of the sensitizer (D*) to the oxidised species in redox mediator (I3-/I-) and from the valence band (VB) of the p-type semiconductor (NiO) to the HOMO level of the dye (e.g. P1, below).
The hole in the VB diffuses to the back contact.
The reduced species in the redox mediator (I-) diffuses to the counter electrode where I3- is regenerated.This completes the circuit generating a cathodic photocurrent.
Our current record is 65 % IPCE with our push-pull dye, P1.