Entity

Time filter

Source Type


Li Y.,Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education | Li Y.,Tsinghua University | Zhang D.,Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education | Zhang D.,Tsinghua University | And 6 more authors.
Science China Chemistry | Year: 2016

High cost of phosphors and significant efficiency roll-off at high brightness are the two main factors that limit the wide application of phosphorescent organic light-emitting diodes (PHOLEDs). Efforts have been paid to find ways to reduce the phosphors’ concentration and efficiency roll-off of PHOLEDs. In this work, we reported red emission PHOLEDs with low dopant concentration and low efficiency roll-off based on a novel host material 2,4-biscyanophenyl-6-(12-phenylindole[2,3-a]carbazole-ll-yl)-l,3,5-triazine (BCPICT), with thermally activated delayed fluorescent (TADF) properties. The device with 1.0% dopant concentration displayed a maximum external quantum efficiency of 10.7%. When the dopant concentration was increased to 2.0%, the device displayed a maximum external quantum efficiency of 10.5% and a low efficiency roll-off of 5.7% at 1000 cd/m2. © 2016, Science China Press and Springer-Verlag Berlin Heidelberg. Source


Haoyuan L.,Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education | Haoyuan L.,Tsinghua University | Liang C.,Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education | Liang C.,Tsinghua University | And 12 more authors.
Science China Chemistry | Year: 2012

The hole and electron mobilities of the amorphous films of the organic semiconductor 4,4'-N,N'-dicarbazole-biphenyl (CBP) at different electric fields were measured through the time of flight (TOF) method. Based on its crystalline structure, the hole and electron mobilities of CBP were calculated. A detailed comparison between experimental and theoretical results is necessary for further understanding its charge transport properties. In order to do this, charge mobilities at zero electric field, 7mu;(0), were deduced from experimental data as a link between experimental and theoretical data. It was found that the electron transport of CBP is less affected by traps compared with its hole transport. This unusual phenomenon can be understood through the distributions of frontier molecular orbitals. We showed that designing materials with frontier molecular orbitals localized at the center of the molecule has the potency to reduce the influence of traps on charge transport and provide new insights into designing high mobility charge transport materials. © Science China Press and Springer-Verlag Berlin Heidelberg 2012. Source

Discover hidden collaborations