Comparison of electron transporting layer in white OLED with a double emissive layer structure

Abstract White organic light-emitting devices consisting of a non-doped ultrathin orange emissive layer (EML) and a doped blue EML were fabricated. The effect of varying electron transporting layers on device performance was studied, while 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, tris(8-hydroxy-quinolinato)aluminum and 1,3,5-tris(2-N-phenylbenzimidazolyl)benzene (TPBi) were employed, respectively. The results showed that by comparing four kinds of ETLs, the TPBi device exhibited a current efficiency of 20.9 cd/A at a current density of 10 mA/cm2 and a maximum external quantum efficiency of 10.0%, while stable white emission with Commission Internationale de l’Eclairage coordinates of (0.39, 0.43) were obtained, attributing to efficient charge transportation and exciton confinement.

[1]  Junsheng Yu,et al.  Detailed analysis of bathocuproine layer for organic solar cells based on copper phthalocyanine and C60 , 2009 .

[2]  Junsheng Yu,et al.  Properties of non-doped organic light-emitting devices based on an ultrathin iridium complex phosphor layer , 2010 .

[3]  Sung Hyun Kim,et al.  Improved color stability in white phosphorescent organic light-emitting diodes using charge confining structure without interlayer , 2007 .

[4]  Young Kwan Kim,et al.  White organic light-emitting diodes showing nearly 100% internal quantum efficiency , 2010 .

[5]  Chih-Hung Hsiao,et al.  Emitting layer thickness dependence of color stability in phosphorescent organic light-emitting devices , 2010 .

[6]  Wei Zhang,et al.  Film thickness influence of dual iridium complex ultrathin layers on the performance of nondoped white organic light-emitting diodes , 2011, Displays.

[7]  Junji Kido,et al.  Pyridine‐Containing Triphenylbenzene Derivatives with High Electron Mobility for Highly Efficient Phosphorescent OLEDs , 2008 .

[8]  Junsheng Yu,et al.  Low operating voltage bright organic light-emitting diode using iridium complex doped in 4,4 ' -bis[N-1-napthyl-N-phenyl-amino]biphenyl , 2007 .

[9]  Bei Chu,et al.  Efficient white organic light-emitting diodes comprising an ultrathin iridium complex sub-monolayer , 2007 .

[10]  Junji Kido,et al.  Highly Efficient Organic Blue‐and White‐Light‐Emitting Devices Having a Carrier‐ and Exciton‐Confining Structure for Reduced Efficiency Roll‐Off , 2008 .

[11]  Changhai Zhang,et al.  Simulation of transform for external quantum efficiency and power efficiency of electroluminescent devices , 2007 .

[12]  Stephen R. Forrest,et al.  White Organic Light‐Emitting Devices for Solid‐State Lighting , 2004 .

[13]  Shui-Tong Lee,et al.  Transient electroluminescence of organic quantum-well light-emitting diodes , 2002 .

[14]  Chih-Hung Hsiao,et al.  Emitting-layer design of white organic light-emitting devices with single-host material , 2009 .

[15]  Young Kwan Kim,et al.  Highly Efficient Green Phosphorescent Organic Light-Emitting Diodes with High Electron Mobility , 2011 .

[16]  S. Forrest,et al.  Highly efficient phosphorescent emission from organic electroluminescent devices , 1998, Nature.

[17]  Shizuo Tokito,et al.  Phosphorescent-sensitized triplet-triplet annihilation in tris(8-hydroxyquinoline) aluminum , 2005 .

[18]  Jung Hyun Park,et al.  Highly efficient white organic light-emitting diodes using two emitting materials for three primary colors (red, green, and blue) , 2007 .

[19]  Evan L. Williams,et al.  Excimer‐Based White Phosphorescent Organic Light‐Emitting Diodes with Nearly 100 % Internal Quantum Efficiency , 2007 .

[20]  Bo Qu,et al.  Recent Progresses on Materials for Electrophosphorescent Organic Light‐Emitting Devices , 2011, Advanced materials.

[21]  Stephen R. Forrest,et al.  High-efficiency organic electrophosphorescent devices with tris(2-phenylpyridine)iridium doped into electron-transporting materials , 2000 .

[22]  Gregor Schwartz,et al.  White organic light-emitting diodes with fluorescent tube efficiency , 2009, Nature.

[23]  Stephen R. Forrest,et al.  Improved energy transfer in electrophosphorescent devices , 1999 .

[24]  S. Forrest,et al.  Nearly 100% internal phosphorescence efficiency in an organic light emitting device , 2001 .

[25]  Ying Zheng,et al.  Effects of triplet energies and transporting properties of carrier transporting materials on blue phosphorescent organic light emitting devices , 2008 .

[26]  X. Cao,et al.  Quenching-enhanced shift of recombination zone in phosphorescent organic light-emitting diodes , 2010 .

[27]  Katsutoshi Nagai,et al.  Multilayer White Light-Emitting Organic Electroluminescent Device , 1995, Science.

[28]  Tetsuo Tsutsui,et al.  High electron mobility in bathophenanthroline , 2000 .

[29]  Karsten Walzer,et al.  Triplet-exciton quenching in organic phosphorescent light-emitting diodes with Ir-based emitters , 2007 .

[30]  Soon-Ki Kwon,et al.  Efficient, Color Stable White Organic Light‐Emitting Diode Based on High Energy Level Yellowish‐Green Dopants , 2008 .

[31]  Jan Kalinowski,et al.  Single-dopant organic white electrophosphorescent diodes with very high efficiency and its reduced current density roll-off , 2007 .

[32]  Raymond Kwong,et al.  Triplet exciton confinement and unconfinement by adjacent hole-transport layers , 2004 .

[33]  Dongge Ma,et al.  Realization of high efficiency orange and white organic light emitting diodes by introducing an ultra-thin undoped orange emitting layer , 2011 .

[34]  Junsheng Yu,et al.  Organic photovoltaic cells based on TPBi as a cathode buffer layer , 2011 .

[35]  K. Walzer,et al.  Influence of charge balance and exciton distribution on efficiency and lifetime of phosphorescent organic light-emitting devices , 2008 .

[36]  Stephen R. Forrest,et al.  Efficient Organic Electrophosphorescent White‐Light‐Emitting Device with a Triple Doped Emissive Layer , 2004 .

[37]  Fumio Sato,et al.  Confinement of triplet energy on phosphorescent molecules for highly-efficient organic blue-light-emitting devices , 2003 .