Brus, V.V.; Gluba, M.A.; Mai, C.-K.; Fronk, S.L.; Rappich, J.; Nickel, N.H.; Bazan, G.C.: Conjugated Polyelectrolyte/Graphene Hetero-Bilayer Nanocomposites Exhibit Temperature Switchable Type of Conductivity. Advanced Electronic Materials 3 (2017), p. 1600515/ 1-7
10.1002/aelm.201600515
Abstract:
Conjugated polyelectrolytes (CPEs) comprise an electronically delocalized backbone that is rendered soluble in high dielectric media through the incorporation of side groups bearing ionic functionalities. This combination of structural components yields soft materials capable of integrating the optoelectronic features of organic semiconductors with the ability of polyelectrolytes to modulate physical properties through electrostatic forces. CPEs have been used to control charge injection barriers in organic optoelectronic devices through interfacial phenomena in which electrostatic dipoles modify the effective work function of adjacent metallic electrodes. Doping preferences of the backbone can also be influenced by the choice of the charged group closest to the backbone, as demonstrated by narrow bandgap molecular frameworks that spontaneously p-dope in water when containing anionic side groups, but remain undoped in the case of the cationic counterparts. These doping preferences also extend to single walled carbon nanotube (SWNT) composites, where the cationic (anionic) CPE yields n-type (p-type) nanocomposites, despite that the same conjugated framework is utilized.