[13a-A405-1~11] 12.2 評価・基礎物性

▼ [13a-A405-10] MIS-CELIV Carrier Mobility Measurement on Triphenylamine-Thienothiophene-Based Hole Transport Material with LiTFSI

〇(DC)WooJin Kim¹、Yuki Nishikawa¹、Thanh-Tuan Bui²、Fabrice Goubard²、Quang-Duy Dao³、Akihiko Fujii¹、Masanori Ozaki¹ (1.Osaka Univ.、2.Cergy-Pontoise Univ.、3.VNU-Univ. of Science)

キーワード：Organic electronics, Hole transport material, Carrier transport properties

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) was developed and applied for hybrid perovskite solar cells[1]. The electronic properties of TT-2,5-TPA could be modified by blending a dopant, such as lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), with considerable advantages to raise the charge carrier concentration[2]. In this paper, the carrier mobility of TT-2,5-TPA with LiTFSI regarding to temperature dependence was studied by metal-insulator-semiconductor charge extraction by the linearly increasing voltage (MIS-CELIV)[3] method. Device structure with TT-2,5-TPA film was composed for the MIS-CELIV measurement. The injected holes were accumulated near the interface of MgF₂/TT-2,5-TPA and extracted through the MoO₃/Au electrode by a sawtooth-wave applying a reversely-biased linearly-increasing voltage bias. The activation energy (E_a) of the TT-2,5-TPA thin film with LiTFSI changed as a function of doping concentration, and was evaluated to be 115-26 meV[4]. The decrease of E_a can be interpreted that most of the localized carriers cause the thermal activation involved with the enhanced hopping rate owing to the LiTFSI doping.
[Acknowledgments] This work was partially supported by the JSPS KAKENHI Grant Numbers 18H04514, and the JSPS Core-to-Core Program A., Advanced Research Networks.
[1] T. H. Le et al., Chem. Asian J. 13, 1302 (2018). [2] K. Neumann et al., RSC Adv. 4, 43550 (2014). [3] G. Juška et al., J. Non-Cryst. Solids 358, 748 (2012). [4] W. Kim et al., Jpn. J. Appl. Phys. 59 (2020) in press.