Carrier transport study on triphenylamine-thienothiophene-based hole transport material by MIS-CELIV method

Charge carrier mobility measurement of a promising hole transport material, 4,4'-(thieno[3,2-b]thiophene-2,5-diyl)bis(N,N-bis(4-methoxyphenyl)aniline) (TT-2,5-TPA), with a p-dopant, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) at various doping concentration, was carried out by utilizing metal-insulator-semiconductor charge extraction by the linearly increasing voltage (MIS-CELIV) method. Doping concentration dependence and temperature dependence of the hole mobility in TT-2,5-TPA thin films with LiTFSI were investigated in the MIS-CELIV measurement, and the enhancement of hole mobility and suppression of activation energy were discussed by taking the thermal activated hopping process into consideration. (C) 2020 The Japan Society of Applied Physics