title: High-Performance Organic Light-Emitting Diode with Substitutionally Boron-Doped Graphene Anode.
abstract: The hole-injection barrier between the anode and the hole-injection layer (HIL) is of critical importance to determine the device performance of organic light-emitting diodes (OLEDs). Here, we report on a record-high external quantum efficiency (EQE) (24.6% in green phosphorescence) of OLEDs fabricated on both rigid and flexible substrates, with the performance enhanced by the use of nearly defect-free and high-mobility boron-doped graphene as an effective anode and hexaazatriphenylene hexacarbonitrile as a new type of HIL. This new structure outperforms the existing graphene-based OLEDs, in which MoO3, AuCl3, or bis(trifluoromethanesulfonyl)amide are typically used as a doping source for the p-type graphene. The improvement of the OLED performance is attributed mainly to the appreciable increase of the hole conductivity in the nearly defect-free boron-doped monolayer graphene, along with the high work function achieved by the use of a newly developed hydrocarbon precursor containing boron in the graphene growth by chemical vapor deposition.
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Tien-Lin
authors.initials: TL
authors.lastname: Wu
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Chao-Hui
authors.initials: CH
authors.lastname: Yeh
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Wen-Ting
authors.initials: WT
authors.lastname: Hsiao
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Pei-Yun
authors.initials: PY
authors.lastname: Huang
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Min-Jie
authors.initials: MJ
authors.lastname: Huang
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Yen-Hsin
authors.initials: YH
authors.lastname: Chiang
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Chien-Hong
authors.identifier: http://orcid.org/0000-0003-3838-6845
authors.initials: CH
authors.lastname: Cheng
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Rai-Shung
authors.initials: RS
authors.lastname: Liu
authors.affiliation: Department of Electrical Engineering and ‡Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Po-Wen
authors.initials: PW
authors.lastname: Chiu
keywords: boron doping; chemical vapor deposition; flexibility; graphene; organic light-emitting diodes; polycyclic aromatic hydrocarbons