Freezing-in orientational disorder induces crossover from thermally-activated to temperature-independent transport in organic semiconductors

Autor: Ward, J. W., McNeil, L. E., Jiang, H., Payne, M. E., Hu, P., Vermeulen, D., Goetz, K. P., Kloc, C., Fonari, A., Coropceanu, V., Jurchescu, O. D., Diemer, P. J., Day, C. S.
Jazyk: angličtina
Rok vydání: 2014
DOI: 10.17615/yhn0-5917
Popis: The crystalline structure of organic materials dictates their physical properties, but while significant research effort is geared towards understanding structure-property relationships in such materials, the details remain unclear. Many organic crystals exhibit transitions in their electrical properties as a function of temperature. One example is the 1:1 charge-transfer complex trans--stilbene-2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane. Here we show that the mobility and resistivity of this material undergo a transition from being thermally activated at temperatures above 235 K to being temperature independent at low temperatures. On the basis of our experimental and theoretical results, we attribute this behaviour to the presence of a glass-like transition and the accompanied freezing-in of orientational disorder of the stilbene molecule.
Databáze: OpenAIRE