High Efficiency Green Phosphorescent Organic Light Emitting Devicesusing the Emission Layer of (TCTA/TCTA₁/₃TAZ₂/₃/TAZ):Ir(ppy)₃

Abstract

We have fabricated and evaluated newNew high high-efficiency green green-light light-emitting phosphorescent devices with an emission layer of [<TEX>$TCTA/TCTA_{1/3}TAZ_{2/3}/TAZ$</TEX>] : <TEX>$Ir(ppy)_3$</TEX> were fabricated and evaluated, and compared the electroluminescence characteristics of these devices were compared with the conventional phosphorescent devices with emission layers of (<TEX>$TCTA_{1/3}TAZ_{2/3}$</TEX>) : <TEX>$Ir(ppy)_3$</TEX> and (TCTA/TAZ) : <TEX>$Ir(ppy)_3$</TEX>. The current density, luminance, and current efficiency of the a device with an emission layer of (<TEX>$80{\AA}-TCTA/90^{\circ}{\AA}-TCTA_{1/3}TAZ_{2/3}/130{\AA}-TAZ$</TEX>) : 10%-<TEX>$Ir(ppy)_3$</TEX> were <TEX>$95\;mA/cm^2$</TEX>, <TEX>$25000\;cd/m^2$</TEX>, 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 <TEX>$400\;cd/m^2$</TEX>. 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 <TEX>$15000\;cd/m^2$</TEX>, the current efficiency of the a device with an emission layer of (<TEX>$80{\AA}-TCTA/90{\AA}-TCTA_{1/3}TAZ_{2/3}/130{\AA}-TAZ$</TEX>) : 10%-<TEX>$Ir(ppy)_3$</TEX> 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 (<TEX>$300{\AA}-TCTA_{1/3}TAZ_{2/3}$</TEX>) : 10%-<TEX>$Ir(ppy)_3$</TEX> and (<TEX>$100{\AA}-TCTA/200{\AA}$</TEX>-TAZ) : 10%-<TEX>$Ir(ppy)_3$</TEX>, respectively.