Manifestation of glass transition in electronic charge transport in Si and Ge Backbone polymers

Autor: Martin A. Abkowitz, Milan Stolka, Frederick E. Knier, Ronald J. Weagley, Kathleen M. McGrane
Rok vydání: 1990
Předmět:
Zdroj: Synthetic Metals. 37:295-303
ISSN: 0379-6779
DOI: 10.1016/0379-6779(90)90160-m
Popis: Electronic transport of photoinjected holes in high molecular weight linear polymers with silicon and germanium backbone is electric field dependent and thermally activated. At fixed electric fields, during both rate and step heating, the mobility activation energies (ϵ) in all these polymers change abruptly and reversibly at critical temperatures (ifT c ) without concurrent abrupt changes in mobilities. These critical temperatures coincide with the respective glass transition temperatures. In all cases, ϵ at T > T g is lower than ϵ at T T g , typically by a factor of 2 to 3. In polymers with aliphatic side groups ϵ ( T > T g ) is extremely low, practically approaching zero. The change of activation near T g is similar to that observed in amorphous charge-transporting polymers and other glasses, including selenium and its alloys. The universality of this phenomenon is emphasized.
Databáze: OpenAIRE