Effect of defect-enhanced molecular oxygen adsorption on the imbalance of hole versus electron mobility in conjugated polymers

Abstract

The generally observed higher hole mobility relative to electron mobility in conjugated polymers is explained with the defects and adsorbed molecular oxygen. Adsorption of the extrinsic molecular oxygen leads to that electrons are bound more tightly than holes by the traps in the originally symmetric electronic system. Hence, the mobility imbalance emerges from the asymmetric binding energies. Besides, the defects are the favored adsorption sites because the intermolecular attraction is enhanced due to stronger induced dipoledipole interaction when gap defect levels appear.

Impedance Spectroscopic Indication for Solid State Electrochemical Reaction in (CH3NH3)PbI3 Films

“…Our results concern the effect of post-deposition exposure to O 2 or air on the net doping density, which, to the best of our knowledge, has not yet been reported. Lower free carrier density as a result of oxygen adsorption has been previously reported for organic semiconductors . Electron sharing between the material and O 2 molecules result in the shared electrons becoming localized and no longer contributing to the free carrier density, i.e., dedoping of n- and doping of p-type material.…”