posted on 2004-12-01, 00:00authored byHyunsik Moon, Roswitha Zeis, Evert-Jan Borkent, Celine Besnard, Andrew J. Lovinger, Theo Siegrist, Christian Kloc, Zhenan Bao
The substitution of chloro or bromo groups in tetracene gives rise to the change of crystal structure, having a substantial effect on carrier transport. Halogenated tetracene derivatives were synthesized and grown into single crystals. Monosubstituted 5-bromo- and 5-chlorotetracenes have the herringbone-type structure, while 5,11-dichlorotetracene has the slipped π stacking structure. Mobility of 5,11-dichlorotetracene was measured to be as high as 1.6 cm2/V·s in single-crystal transistors. The π stacking structure, which enhances π orbital overlap and facilitates carrier transport, may thus be responsible for this high mobility.