Abstract
From first-principles calculations we determine the Coulomb interaction between two holes on oligo-acene and -thiophene molecules in a crystal, as a function of the oligomer length. The electronic polarization of the molecules that surround the charged oligomer reduces the bare Coulomb repulsion between the holes by approximately a factor of 2. The effects of relaxing the molecular geometry in the presence of holes is found to be significantly smaller. In all cases the effective hole-hole repulsion is much larger than the valence bandwidth, which implies that at high doping levels the properties of these organic semiconductors are determined by electron-electron correlations.
Original language | English |
---|---|
Article number | 146405 |
Number of pages | 4 |
Journal | Physical review letters |
Volume | 93 |
Issue number | 14 |
DOIs | |
Publication status | Published - 2004 |