Lin H.-Y.Chen C.-H.Lee Y.-T.Chiu T.-L.JIUN-HAW LEEChen C.-T.Adachi C.2022-04-252022-04-25202119448244https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111603538&doi=10.1021%2facsami.1c07859&partnerID=40&md5=72f40f25e86720c79f42323bbade2f50https://scholars.lib.ntu.edu.tw/handle/123456789/607220A novel bis-4Ph-substituted 9,10-dipehnylanthracene deep blue [1931 CIE (0.15, 0.08)] fluorescent compound, AnB4Ph, has been synthesized and characterized for organic light-emitting diode (OLED) applications. Our experimental study of AnB4Ph excludes the possibility of triplet-triplet annihilation, hybridized local and charge transfer, or thermally activated delayed fluorescent characteristics of the material. Since the solid-state photoluminescence quantum yield of AnB4Ph was determined to be 48%, assuming a 100% for the charge recombination efficiency, the light outcoupling efficiency (ηout) of an AnB4Ph non-doped OLED achieving an external quantum efficiency (EQE) of 5.3% is at least 44%, which is more than twofold higher than 20% for conventional OLEDs. Both grazing incidence wide-angle X-ray scattering (GIWAXS) and angle-dependent photoluminescence (ADPL) measurements reveal AnB4Ph having a high value of order parameter (SGIWAXS) of 0.61 for a ππstacking along the normal direction and an orientation order parameter (SADPL) for a horizontal emitting dipole moment of -0.50 or Θ (horizontal-dipole ratios) of 100%, respectively. Otherwise, a refractive index (n) measurement provides a n = 1.80 for AnB4Ph thin films. Based on ηout = 1.2 × n-2, the calculated ηout is 37%, which is also in accordance with the results of GIWAXS and ADPL. We have also fabricated the classical fluorescent DPAVBi-doped AnB4Ph OLEDs, which display a true blue [1931 CIE (0.15 and 0.16)] electroluminescence with a high efficiency (EQE = 6.9%), surpassing the conventional ?5% EQE. Based on an ηout of 42% for DPAVBi-doped AnB4Ph OLEDs, our studies suggest that the extremely horizontally aligned AnB4Ph host material exerts the same horizontal alignment on the DPAVBi dopant molecules. ? 2021 American Chemical Society.deep blue OLEDsfluorescence materialshorizontal orientationlight outcoupling efficiencylight-emitting diodemolecular orientationnon-doped OLEDstransition dipole momentCharge transferEfficiencyElectroluminescenceFluorescenceLightOrganic light emitting diodes (OLED)PhotoluminescenceQuantum theoryRefractive indexSupercomputersX ray scatteringCharge recombinationsExternal quantum efficiencyFluorescent characteristicFluorescent compoundsHorizontal alignmentPhotoluminescence quantum yieldsThermally activatedTriplet-triplet annihilationQuantum efficiencyjournal article10.1021/acsami.1c07859342646442-s2.0-85111603538