• Korean Journal of Materials Research
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• v.18 no.7
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• pp.347-351
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• 2008

We have fabricated and evaluated newNew high high-efficiency green green-light light-emitting phosphorescent devices with an emission layer of [$TCTA/TCTA_{1/3}TAZ_{2/3}/TAZ$] : $Ir(ppy)_3$ were fabricated and evaluated, and compared the electroluminescence characteristics of these devices were compared with the conventional phosphorescent devices with emission layers of ($TCTA_{1/3}TAZ_{2/3}$) : $Ir(ppy)_3$ and (TCTA/TAZ) : $Ir(ppy)_3$. The current density, luminance, and current efficiency of the a device with an emission layer of ($80{\AA}-TCTA/90^{\circ}{\AA}-TCTA_{1/3}TAZ_{2/3}/130{\AA}-TAZ$) : 10%-$Ir(ppy)_3$ were $95\;mA/cm^2$, $25000\;cd/m^2$, and 27 cd/A at an applied voltage of 10 V, respectively. The maximum current efficiency was 52 cd/A under the a luminance value of $400\;cd/m^2$. The peak wavelength and FWHM (FWHM (full width at half maximum) in the electroluminescence spectral were 513 nm and 65 nm, respectively. The color coordinate was (0.30, 0.62) on the CIE (Commission Internationale de I'Eclairage) chart. Under the a luminance of $15000\;cd/m^2$, the current efficiency of the a device with an emission layer of ($80{\AA}-TCTA/90{\AA}-TCTA_{1/3}TAZ_{2/3}/130{\AA}-TAZ$) : 10%-$Ir(ppy)_3$ was 34 cd/A, which has beenshowed an improvement of improved 1.7 and 1.4 times compared to those of the devices with emission layers of ($300{\AA}-TCTA_{1/3}TAZ_{2/3}$) : 10%-$Ir(ppy)_3$ and ($100{\AA}-TCTA/200{\AA}$-TAZ) : 10%-$Ir(ppy)_3$, respectively.

• Journal of IKEEE
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• v.24 no.3
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• pp.699-705
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• 2020

In this study, a facial way to enhance the electrical properties of organic light-emitting diodes (OLEDs) via the solution process doping method based on the poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl) diphenylamine)] (TFB) as a hole transporting layer (HTL) is demonstrated. In the TFB solution of the hole transport material, 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN) was doped by 3 wt% to improve the electrical properties of the HTL. According, the OLED with HAT-CN doped TFB showed the increased current density and luminance at the same driving voltage on behalf of the improved conductivity of HTL, and the reduced turn-on voltage from 13 V to 9 V. Furthermore, the maximum external quantum efficiency was dramatically increased three times from 3.6 to 10.8 % compared to the reference device without appling doping methode.