MIS-CELIV Carrier Mobility Measurement on Triphenylamine-Thienothiophene-BasedHole Transport Material with LiTFSI

摘要

Recently, a hole transport material,4,4’-(thieno[3,2-b]thiophene-2,5-diyl)bis(N,N-bis(4-methoxyphenyl)aniline) (TT-2,5-TPA) (Fig. 1) was developed and applied for hybridperovskite solar cells. The electronic properties of TT-2,5-TPA couldbe modified by blending a dopant, such as lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI), with considerableadvantages to raise the charge carrier concentration. In this paper, thecarrier mobility of TT-2,5-TPA with LiTFSI regarding to temperaturedependence was studied by metal-insulator-semiconductor chargeextraction by the linearly increasing voltage (MIS-CELIV) method.Device structure with TT-2,5-TPA film wascomposed for the MIS-CELIV measurement as shown in Fig. 2. Theinjected holes were accumulated near the interface of MgF2/TT-2,5-TPAand extracted through the MoO_3/Au electrode by a sawtooth-waveapplying a reversely-biased linearly-increasing voltage bias.