Dear colleagues,
Now I am working on BHJ solar cells with inverted structure.
I have a case where the cathode's WF (~3.8 eV) is lower than acceptor LUMO (~3.9 eV). What would happen if the cathode's WF is lower than acceptor LUMO? will it be good or bad thing?
I read a paper (10.1002/admi.201400397) showing similar case with my research, where their cathode's WF is lower than acceptor LUMO improving the device performance. But, I am still doubt about it..
Thank you,
Sincerely,
Adi Prasetio
Dear Adi Prasetio ,
welcome,
You are right. For correct operation of the bhj scs it is optimum to make the work function of the cathode is slightly greater than the lumolevel of the acceptor .
material. When the work function is lower this will impede the transport of electrons from the acceptor material tro the cathode. As this difference gets smaller, its impedance to the transport will be reduced.
When the work function gets greater then the electron can be transport easily to the cathode however the contact difference of potential of the solar cell will be smaller leading to smaller open circuit voltage.
I assumed that you cathode is directly contacting your acceptor layer.
For more information please follow the paper in the link: Conference Paper Generic Analytical Models for Organic and Perovskite Solar Cells
best wishes
Dear Adi Prasetio ,
welcome,
You are right. For correct operation of the bhj scs it is optimum to make the work function of the cathode is slightly greater than the lumolevel of the acceptor .
material. When the work function is lower this will impede the transport of electrons from the acceptor material tro the cathode. As this difference gets smaller, its impedance to the transport will be reduced.
When the work function gets greater then the electron can be transport easily to the cathode however the contact difference of potential of the solar cell will be smaller leading to smaller open circuit voltage.
I assumed that you cathode is directly contacting your acceptor layer.
For more information please follow the paper in the link: Conference Paper Generic Analytical Models for Organic and Perovskite Solar Cells
best wishes
The WF of the electrode should be higher than the LUMO of acceptor, otherwise the efficient transport of electrons to cathode will be hampered. Try to change the electrode for your material.
I am surprised about the choice of metal as your cathode because we generally usein case of inverted structure. Al or Ag which inherently possess high WF (4 eV).
- Badges
- Science topic