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

Abstract

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.