title: Dibenzothiophene Sulfone-Based Phosphine Oxide Electron Transporters with Unique Asymmetry for High-Efficiency Blue Thermally Activated Delayed Fluorescence Diodes.
abstract: Three asymmetrical electron transporters as dibenzothiophene sulfone (DBSO)-diphenylphosphine oxide (DPPO) hybrids, collectively named mnDBSODPO, were designed and prepared. All of these materials achieve the high triplet energy of ∼3.0 eV to restrain the exciton linkage from emissive layers. The dependence of inductive and steric effects for DPPO groups on the substitution position, the intermolecular interaction suppression, the encapsulations of high-polar DBSO cores, and the favorable electrical performance are successfully integrated on 36DBSODPO, which can simultaneously suppress the exciton quenching by formation of an interfacial dipole and enhancing the charge flux balance. As a result, 36DBSODPO endowed its tetralayer blue thermally activated delayed fluorescence (TADF) devices with impressive performance, including the maximum external quantum efficiency around 19%, and reduced efficiency roll-offs, which verifies the great potential of asymmetrical electron transporting materials for highly efficient TADF devices.
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Material Science, Heilongjiang University , 74 Xuefu Road, Harbin 150080, China.
authors.forename: Chaochao
authors.initials: C
authors.lastname: Fan
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Material Science, Heilongjiang University , 74 Xuefu Road, Harbin 150080, China.
authors.forename: Chunbo
authors.initials: C
authors.lastname: Duan
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Material Science, Heilongjiang University , 74 Xuefu Road, Harbin 150080, China.
authors.forename: Chunmiao
authors.initials: C
authors.lastname: Han
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Material Science, Heilongjiang University , 74 Xuefu Road, Harbin 150080, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Han
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Material Science, Heilongjiang University , 74 Xuefu Road, Harbin 150080, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
keywords: asymmetrical configuration; electron transporting material; interfacial effect; phosphine oxide; thermally activated delayed fluorescence