Highly efficient phosphorescent blue and white organic light-emitting devices with simplified architectures

Abstract Blue phosphorescent organic light-emitting devices (PhOLEDs) with quantum efficiency close to the theoretical maximum were achieved by utilizing a double-layer architecture. Two wide-triplet-gap materials, 1,3-bis(9-carbazolyl)benzene and 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, were employed in the emitting and electron-transport layers respectively. The opposite carrier-transport characteristics of these two materials were leveraged to define the exciton formation zone and thus increase the probability of recombination. The efficiency at practical luminance (100 cd/m 2 ) was as high as 20.8%, 47.7 cd/A and 31.2 lm/W, respectively. Furthermore, based on the design concept of this simplified architecture, efficient warmish-white PhOLEDs were developed. Such two-component white organic light-emitting devices exhibited rather stable colors over a wide brightness range and yielded electroluminescence efficiencies of 15.3%, 33.3 cd/A, and 22.7 lm/W in the forward directions.

[1]  Jang‐Joo Kim,et al.  A highly efficient wide-band-gap host material for blue electrophosphorescent light-emitting devices , 2007 .

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

[3]  C. Lennartz,et al.  Effect of Electric Field on Coulomb‐Stabilized Excitons in Host/Guest Systems for Deep‐Blue Electrophosphorescence , 2009 .

[4]  Richard H. Friend,et al.  Electrical degradation of triarylamine-based light-emitting polymer diodes monitored by micro-Raman spectroscopy , 2004 .

[5]  Efficient White OLEDs Employing Phosphorescent Sensitization , 2007, Journal of Display Technology.

[6]  Ying Zheng,et al.  Efficient deep-blue phosphorescent organic light-emitting device with improved electron and exciton confinement , 2008 .

[7]  Chih‐Hao Chang,et al.  Efficient phosphorescent white OLEDs with high color rendering capability , 2010 .

[8]  Yun Chi,et al.  New Dopant and Host Materials for Blue‐Light‐Emitting Phosphorescent Organic Electroluminescent Devices , 2005 .

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

[10]  D. Hertel,et al.  Triplet-polaron quenching in conjugated polymers. , 2007, The journal of physical chemistry. B.

[11]  Chih‐Hao Chang,et al.  Efficient phosphorescent white organic light-emitting devices incorporating blue iridium complex and multifunctional orange-red osmium complex , 2009 .

[12]  Jeong-Ik Lee,et al.  Influence of Doping Profile on the Efficiency of Blue Phosphorescent Organic Light-emitting Diodes , 2008 .

[13]  Stephen R. Forrest,et al.  Transient analysis of organic electrophosphorescence: I. Transient analysis of triplet energy transfer , 2000 .

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

[15]  C. Tang,et al.  Organic Electroluminescent Diodes , 1987 .

[16]  A. Bolognesi,et al.  All-Conjugated Diblock Copolymer Approach To Improve Single Layer Green Electroluminescent Devices† , 2011 .

[17]  Zhiqiang Gao,et al.  Blocking reactions between indium-tin oxide and poly (3,4-ethylene dioxythiophene):poly(styrene sulphonate) with a self-assembly monolayer , 2002 .

[18]  Ken-Tsung Wong,et al.  Highly Efficient Organic Blue Electrophosphorescent Devices Based on 3,6‐Bis(triphenylsilyl)carbazole as the Host Material , 2006 .

[19]  Chih‐Hao Chang,et al.  Efficient iridium(III) based, true-blue emitting phosphorescent OLEDS employing both double emission and double buffer layers , 2009 .

[20]  F. So,et al.  High efficiency blue phosphorescent organic light-emitting device , 2008 .

[21]  J. Kido,et al.  Pyridine-Containing Bipolar Host Materials for Highly Efficient Blue Phosphorescent OLEDs , 2008 .

[22]  Jan Kalinowski,et al.  Electric-field-induced quenching of photoluminescence in photoconductive organic thin film structures based on Eu3+ complexes , 2006 .

[23]  Junji Kido,et al.  High Luminous Efficiency Blue Organic Light-Emitting Devices Using High Triplet Excited Energy Materials , 2007 .

[24]  S. Jeon,et al.  High‐Efficiency Deep‐Blue‐Phosphorescent Organic Light‐Emitting Diodes Using a Phosphine Oxide and a Phosphine Sulfide High‐Triplet‐Energy Host Material with Bipolar Charge‐Transport Properties , 2010, Advanced materials.

[25]  Yun Chi,et al.  Blue-emitting heteroleptic iridium(III) complexes suitable for high-efficiency phosphorescent OLEDs. , 2007, Angewandte Chemie.

[26]  Chihaya Adachi,et al.  100% phosphorescence quantum efficiency of Ir(III) complexes in organic semiconductor films , 2005 .

[27]  Chen‐Han Chien,et al.  A Bipolar Host Material Containing Triphenylamine and Diphenylphosphoryl‐Substituted Fluorene Units for Highly Efficient Blue Electrophosphorescence , 2009 .

[28]  Stephen R. Forrest,et al.  Ultrahigh energy gap hosts in deep blue organic electrophosphorescent devices , 2004 .

[29]  J. Lee,et al.  Effects of charge balance on device performances in deep blue phosphorescent organic light-emitting diodes , 2010 .

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

[31]  Zhenghong Lu,et al.  Efficient single layer RGB phosphorescent organic light-emitting diodes , 2009 .

[32]  Stephen R. Forrest,et al.  Blue organic electrophosphorescence using exothermic host–guest energy transfer , 2003 .