Carrier transport property of truxene discotic liquid crystals with three different ring substituents

摘要

In this study, the charge carrier transport property of 3,8,13-trioctyloxytruxene [Trx(OC8)3] and its analogues, to which two different ring substituents of hydroxyl [Trx(OH) 3(OC8) 3] and methoxy [Trx(OMe)3(OC8)3] groups are introduced, has been studied relative to mesomorphism. Three analogues exhibit a hexagonal columnar (Col(h)) mesophase and their thermal stability increases with the introduction of hydroxyl and methoxy groups. The drift mobility measurements of Trx(OC8)3 and Trx(OH)3(OC8)3 reveal that the drift mobility is on the order of 5 x 10(-2)cm(2)V(-1) s(-1) in the Colh phase and it increases to 10(-1)cm(2)V(-1) s(-1) at the Colh-metastable phase transition, although Trx(OMe)3(OC8)3 shows a drift mobility of 1 x 10(-2)cm(2)V(-1) s(-1) in the Colh phase with temperature dependence. These results indicate that truxene with three alkoxy chains is an interesting molecular core for mesophase semiconductors. (C) 2016 The Japan Society of Applied Physics