We investigate polyethylene imine and diazonium salts as stable, complementary dopants on graphene. Transport in graphene devices doped with these molecules exhibits asymmetry in electron and hole conductance. The conductance of one carrier is preserved, while the conductance of the other carrier decreases. Simulations based on nonequilibrium Green's function formalism suggest that the origin of this asymmetry is imbalanced carrier injection from the graphene electrodes caused by misalignment of the electrode and channel neutrality points.
@article{arxiv.0812.1742,
title = {Chemical Doping and Electron-Hole Conduction Asymmetry in Graphene Devices},
author = {Damon B. Farmer and Roksana Golizadeh-Mojarad and Vasili Perebeinos and Yu-Ming Lin and George S. Tulevski and James C. Tsang and Phaedon Avouris},
journal= {arXiv preprint arXiv:0812.1742},
year = {2015}
}