2
$\begingroup$

In the context of organic solar cells, electron-hole dissociation is sometimes mentioned with regard to excitons (refs 1, 2) and sometime with regard to geminate pairs (refs 3, 4).

Also, exciton binding energy is 10meV (Wannier) - 1eV (Frenkel), while geminate pair binding energy is generally up to 0.5eV.

So what's the difference between an exciton and a geminate pair?

$\endgroup$

1 Answer 1

1
$\begingroup$

A geminate pair can be considered as a charge-transfer exciton, i.e., when an electron from the electron-hole (exciton) pair in some homogeneous material experiences a transfer through the interface between electron donor and electron acceptor materials. The electron in the electron-accepting material and the hole in the electron-donor material remain bound by electrostatic interaction, so they exist as a geminate pair. The binding energy of this pair is less as compared to the exciton in the homogeneous medium by the difference in electron affinities of the contacting materials.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.