title: The first tandem, all-exciplex-based WOLED.
abstract: Exploiting our recently developed bilayer interface methodology, together with a new wide energy-gap, low LUMO acceptor (A) and the designated donor (D) layers, we succeeded in fabricating an exciplex-based organic light-emitting diode (OLED) systematically tuned from blue to red. Further optimization rendered a record-high blue exciplex OLED with η(ext) of 8%. We then constructed a device structure configured by two parallel blend layers of mCP/PO-T2T and DTAF/PO-T2T, generating blue and yellow exciplex emission, respectively. The resulting device demonstrates for the first time a tandem, all-exciplex-based white-light OLED (WOLED) with excellent efficiencies η(ext): 11.6%, η(c): 27.7 cd A(-1), and η(p): 15.8 ml W(-1) with CIE(0.29, 0.35) and CRI 70.6 that are nearly independent of EL intensity. The tandem architecture and blend-layer D/A (1:1) configuration are two key elements that fully utilize the exciplex delay fluorescence, providing a paragon for the use of low-cost, abundant organic compounds en route to commercial WOLEDs.
authors.affiliation: Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, 20224, Taiwan.
authors.forename: Wen-Yi
authors.initials: WY
authors.lastname: Hung
authors.affiliation: Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, 20224, Taiwan.
authors.forename: Guan-Cheng
authors.initials: GC
authors.lastname: Fang
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Lin
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Shuo-Hsien
authors.initials: SH
authors.lastname: Cheng
authors.affiliation: 1] Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan [2] Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan.
authors.forename: Ken-Tsung
authors.initials: KT
authors.lastname: Wong
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Ting-Yi
authors.initials: TY
authors.lastname: Kuo
authors.affiliation: 1] Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan [2] Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, 10617, Taiwan.
authors.forename: Pi-Tai
authors.initials: PT
authors.lastname: Chou