Efficient organic light-emitting diodes through up-conversion from triplet to singlet excited states of exciplexes

2012 ◽  
Vol 101 (2) ◽  
pp. 023306 ◽  
Author(s):  
Kenichi Goushi ◽  
Chihaya Adachi
2019 ◽  
Vol 7 (29) ◽  
pp. 8874-8887 ◽  
Author(s):  
Jianzhong Fan ◽  
Yuchen Zhang ◽  
Kai Zhang ◽  
Jie Liu ◽  
Guanyu Jiang ◽  
...  

Fluorescent emitters with long exciton lifetime and high luminescence efficiency show promising application in organic light emitting diodes (OLEDs), especially those with an aggregation induced emission (AIE) feature.


2019 ◽  
Vol 5 (6) ◽  
pp. eaav9857 ◽  
Author(s):  
Mingchen Xie ◽  
Chunmiao Han ◽  
Qianqian Liang ◽  
Jing Zhang ◽  
Guohua Xie ◽  
...  

Organic light-emitting diodes using cluster emitters have recently emerged as a flexible optoelectronic platform to extend their biological and optical applications. However, their inefficient cluster-centered excited states and deficient electrical properties limit device performance. Here, we introduce donor groups in organic ligands to form ligand-activated clusters, enabling the fabrication of the first cluster-based sky blue–emitting device with a record 30- and 8-fold increased luminance and external quantum efficiency up to ~7000 nits and ~8%, respectively. We show that the electron-donating effect of donor groups can enhance ligand-centered transitions and thoroughly eliminate cluster-centered excited states by delocalizing the molecular transition orbitals from the cluster unit to the ligand, leading to 13-fold increased photoluminescence quantum yield. In turn, the excellent rigidity and photostability of the cluster unit improve the color purity and efficiency stability of the devices. These results will motivate the further development of high-performance optoelectronic clusters by ligand engineering.


2018 ◽  
Vol 6 (21) ◽  
pp. 5721-5726 ◽  
Author(s):  
Peisen Yuan ◽  
Xianfeng Qiao ◽  
Donghang Yan ◽  
Dongge Ma

Triplet excited states in exciplex-based organic light emitting diodes (OLEDs) can be wasted by transferring their energy to the host material in a system with smaller triplet energy levels.


2020 ◽  
Vol 8 (14) ◽  
pp. 4754-4762 ◽  
Author(s):  
Bing Zhang ◽  
Haozhong Wu ◽  
Zhiming Wang ◽  
Anjun Qin ◽  
Ben Zhong Tang

PLICT molecules have twisted structures in the ground state, which are conducive to transport, while the planar conformations of the excited states facilitate radiation. Based on these advantages, they can serve as excellent emitters and hosts in OLEDs.


2018 ◽  
Vol 6 (30) ◽  
pp. 8219-8225 ◽  
Author(s):  
Heather F. Higginbotham ◽  
Piotr Pander ◽  
Renata Rybakiewicz ◽  
Marc K. Etherington ◽  
Subashani Maniam ◽  
...  

A new TADF emitter is presented showing near-infrared efficient emission.


2020 ◽  
Author(s):  
Heather Higginbotham ◽  
Masato Okazaki ◽  
Piotr de Silva ◽  
Satoshi Minakata ◽  
Youhei Takeda ◽  
...  

Room temperature phosphorescence materials offer great opportunities for applications in optoelectronics, due to their unique photophysical characteristics. However, purely organic emitters that can realize distinct electrophosphorescence are rarely exploited. Herein a new approach for designing heavy-atom-free organic room temperature phosphorescence emitters for organic light-emitting diodes is presented. The subtle tuning of the energy diagrams of singlet and triplet excited states by appropriate choice of host matrix allows tailored emission properties and switching of emission channels between thermally activated delayed fluorescence and room temperature phosphorescence. Moreover, an efficient and heavy-atom-free room temperature phosphorescence organic light-emitting diodes using the developed emitter is realized.


2010 ◽  
Vol 378 (1-3) ◽  
pp. 47-57 ◽  
Author(s):  
J. Kalinowski ◽  
M. Cocchi ◽  
L. Murphy ◽  
J.A.G. Williams ◽  
V. Fattori

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