Transfer doping of Graphene by Species of Extreme Work Function

TL;DR

This study uses density functional calculations to explain how species with extreme work functions can dope graphene via charge transfer without damaging its structure, maintaining high mobility.

Contribution

It provides a detailed theoretical explanation of charge transfer doping mechanisms for various species on graphene, emphasizing non-destructive physisorption.

Findings

Certain dopants increase carrier density without creating defects.

Reactive radicals like -OH cause basal plane puckering and defects.

Non-reactive dopants preserve graphene's high mobility.

Abstract

Density functional calculations are used to explain the charge transfer doping mechanism by which species physisorptively bonded to graphene can increase its free hole or electron density, without giving rise to defects, and thus maintain a high carrier mobility. Typical dopants studied are FeCl3, AuCl3, SbF5, HNO3, MoO3, Cs2O and O2. These systems do not break the {\pi} bonding of the basal plane are particularly important as these do not degrade the carrier mobility. In contrast, more reactive radicals like -OH cause a puckering of the basal plane and thereby act as defects.