Exciton dissociation mediated by phonons in organic photovoltaics
Autor: | Fomichev, Stepan, Ruocco, Leonard, Tully, Alexandra, Berciu, Mona |
---|---|
Rok vydání: | 2023 |
Předmět: | |
Druh dokumentu: | Working Paper |
DOI: | 10.1103/PhysRevB.107.195121 |
Popis: | It is well known that phonons can overscreen the bare Coulomb electron-electron repulsion, turning it into the effective attraction that binds the Cooper pairs responsible for BCS superconductivity. Here, we use a simple lattice model to prove that the counterpart of this is also possible, whereby phonons overscreen the bare electron-hole attraction and may turn it repulsive at short distances, driving exciton dissociation in certain regions of the parameter space. We argue that this phonon-mediated short-range screening plays an important role in the physics of organic solar cell materials (and other materials with strong electron-phonon coupling) and could point the way to new strategies for optimizing their efficiencies. Comment: 11 pages, 6 figures |
Databáze: | arXiv |
Externí odkaz: |