• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.647-652
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• 2009

A novel spiro-type host material, 5-[4-(1-naphthyl)phenyl]-spiro[fluorene-7,9'-benzofluorene] (BH-1PN) and three new dopants, namely, 5-[diphenylamino)phenyl]-spiro[fluorene-7,9'-benzofluorene] (BH-1TPA), 5-[4-(N-phenyl (m-tolyl)amino]-spiro[fluorene-7,9'-benzofluorene] (BH-1MDPA) and 5-[(N-phenyl)-2-naphthyl]amino-spiro[fluorene- 7,9'-benzofluorene] (BH-1NPA) were designed and successfully prepared using the Suzuki or amination reactions. The electroluminescence characteristics of BH-1PN as a blue host material doped with each of the blue dopants were evaluated. The structure of the device is ITO/DNTPD/NPB/BH-1PN:5% dopant/Alq3/Al-LiF. The device obtained from BH-1PN doped with diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)phenyl]-amine (BD-1) showed good color purity, efficiency, luminance, and current-density characteristics.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.863-868
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• 2009

New spiro[fluorene-7,9′-benzofluorene]-based blue host material, 5-phenyl-spiro[fluorene-7,9′-benzofluorene] (BH-1P), was successfully prepared by reacting 5-bromo-spiro[fluorene-7,9′-benzofluorene] (1) with phenyl boronic acid through the Suzuki reaction. 5-(N,N-Diphenyl)amino-spiro[fluorene-7,9′-benzofluorene] (BH-1DPA) and diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)-phenyl]amine (BD-1) were used as dopant materials. 2,5-Bis-(2',2"- bipyridin-6-yl)-1,1-diphenyl-3,4-diphenylsilacyclopentadiene (ET4) and Alq3 were used as electron transfer materials. Their UV absorption, photoluminescence and thermal properties were examined. The blue OLEDs with the configuration of ITO/DNTPD/$\alpha$-NPD/BH-1P:5% dopant/$Alq_3$ or ET4/LiF-Al prepared from the BH-1P host and BH-1DPA and BD-1 dopants showed a blue EL spectrum at 452 nm at 10 V and a luminance of 923.9 cd/$m^2$ with an efficiency of 1.27 lm/W at a current density of 72.57 mA/$cm^2$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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• pp.29-30
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• 2008

New spiro-type host materials, 5'-phenylnaphthyl-spiro[fluorene-7,9'-benzofluorene](BH-lPN) and 5',6-bis(phenylnaphthyl)-spiro[fluorene-7,9'-benzofluorene](BH-6PN) were designed and successfully prepared by the Suzki reaction. The EL characteristics of BH-1PN as blue host material doped with blue dopant materials, BD-1 were evaluated and compared with the existing host MADN:dopant BD-1 system. The structure of the device is ITO/DNTPD/NPB/Host:5% dopant/Alq3/Al-LiF. The device obtained from BH-lPN doped with BD-1 showed a good color purity and efficiency, on the other hand luminance and current-density characteristics are worse than that of MADN doped with BD-1.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1414-1420
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• 2013

Five novel spiro[benzo[c]fluorene-7,9'-fluorene] based dyes, including 5-[spiro[benzo[c]fluorene-7,9'-fluoren]-5-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (7), 5-[spiro[benzo[c]fluorene-7,9'-fluoren]-9-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (8), 5-[spiro[benzo[c]fluorene-7,9'-fluoren]-2'-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (9), 9-[spiro[benzo[c]fluorene-7,9'-fluoren]-9-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (10), and 2'-[spiro[benzo[c]-fluorene-7,9'-fluoren]-2'-yl] spiro[benzo[c]fluorene-7,9'-fluorene] (11) were successfully prepared from the corresponding halogen and boronic acid derivatives through the Suzuki coupling reaction, respectively. Chemical structures were confirmed by $^1H$ nuclear magnetic resonance (NMR), $^{13}C$ NMR, Fourier transforminfrared spectrscopy, mass spectroscopy, and elemental analysis. The thermal properties were determined by differential scanning calorimetry and thermal gravimetric analysis. The relationships between the optical and electrochemical properties and the combined positions between these dimers were systematically investigated using UV-vis, photoluminescence (PL), and photoelectron spectroscopy. These five dimers exhibited high fluorescent quantum yields and good morphological stability with high glass transition states > $174^{\circ}C$. Dimer 7 showed a UV absorbance peak at 353 nm, emission PL peak at 424 nm, and quantum efficiency of 0.62 in a cyclohexane solution.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2955-2960
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• 2010

Spiro-type orange phosphorescent host materials, 9-diphenylphosphine oxide-spiro[fluorene-7,9'-benzofluorene] (OPH-1P) and 5-diphenylphosphine oxide-spiro[fluorene-7,9'-benzofluorene] (OPH-2P) were successfully prepared by a lithiation reaction followed by a phosphination reaction with diphenylphosphinic chloride. The EL characteristics of OPH-1P and OPH-2P as orange host materials doped with iridium(III) bis(2-phenylquinoline)acetylacetonate ($Ir(pq)_2acac$) were evaluated. The electroluminescence spectra of the ITO (150 nm)/DNTPD (60 nm)/NPB (30 nm)/OPH-1P or OPH-2P: $Ir(pq)_2acac$ (30 nm)/BCP (5 nm)/$Alq_3$ (20 nm)/LiF (1 nm)/Al (200 nm) devices show a narrow emission band with a full width at half maximum of 75 nm and $\lambda_{max}$ = 596 nm. The device obtained from OPH-1P doped with 3% $Ir(pq)_2acac$ showed an orange color purity of (0.580, 0.385) and an efficiency of (14 cd/A at 7.0 V). The ability of the OPH-P series to combine a high triple energy with a low operating voltage is attributed to the inductive effect of the P=O moieties and subsequent energy lowering of the LUMO, resulting in the enhancement of both the electron injection and transport in the device. The overall result is a device with an EQE > 8% at high brightness, but operating voltage of less than 6.4 V, as compared to the literature voltages of ~10 V.