scholarly journals Efficient electroluminescent hybridized local and charge-transfer host materials with small singlet–triplet splitting to enhance exciton utilization efficiency: excited state transition configuration

RSC Advances ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 6658-6680
Author(s):  
Jayaraman Jayabharathi ◽  
Venugopal Thanikachalam ◽  
Ganapathy Abirama Sundari
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
State Transition ◽  
Utilization Efficiency ◽  
Triplet Splitting ◽  
Host Materials

CDDPI:Ir(ppy)3 exhibits higher efficiencies: L = 8812 cd m−2; ηex = 19.0%; ηc = 27.5 cd A−1; ηp = 33.0 lm W−1 at 2.7 V.

Intramolecular hydrogen bond – enhanced electroluminescence performance of hybridized local and charge transfer (HLCT) excited-state blue-emissive materials

2021 ◽  
Author(s):  
Wan Li ◽  
Pongsakorn Chasing ◽  
Wachara Benchaphanthawee ◽  
Phattananawee Nalaoh ◽  
Thanyarat Chawanpunyawat ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Hydrogen Bond ◽  
Utilization Efficiency ◽  
High Brightness ◽  
Singlet Exciton ◽  
High Maximum ◽  
Intramolecular Hydrogen

OLED devices based on o-hydroxyphenyl phenanthroimidazole (HPI) emitters showed a high maximum external quantum effciency of 8.13% with high brightness of 18 100 cd m−2 and a maximum singlet exciton utilization efficiency of as high as 94%.

Fluorinated 9,9′-bianthracene derivatives with twisted intramolecular charge-transfer excited states as blue host materials for high-performance fluorescent electroluminescence

2014 ◽  
Vol 2 (44) ◽  
pp. 9375-9384 ◽  
Author(s):  
Yue Yu ◽  
Bo Jiao ◽  
Zhaoxin Wu ◽  
Zhanfeng Li ◽  
Lin Ma ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Excited States ◽  
High Performance ◽  
Intramolecular Charge Transfer ◽  
Twisted Intramolecular Charge Transfer ◽  
Host Materials

We report the electroluminescent performance of a series of fluorinated 9,9′-bianthracene derivatives with particular twisted intramolecular charge transfer excited state to serve as host materials.

scholarly journals Reverse intersystem crossing from upper triplet levels to excited singlet: a ‘hot excition’ path for organic light-emitting diodes

2015 ◽  
Vol 373 (2044) ◽  
pp. 20140318 ◽  
Author(s):  
Dehua Hu ◽  
Liang Yao ◽  
Bing Yang ◽  
Yuguang Ma
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Utilization Efficiency ◽  
Intersystem Crossing ◽  
Photophysical Process ◽  
Light Emitting ◽  
Organic Light ◽  
Material Systems

Since researches on the fate of highly excited triplet states demonstrated the existence of reverse intersystem crossing (RISC) from upper triplet levels to singlet manifold in naphthalene, quinoline, isoquinoline, etc. in the 1960s, this unique photophysical process was then found and identified in some other aromatic materials. However, the early investigations mainly focus on exploring the mechanism of this photophysical process; no incorporation of specific application was implemented. Until recently, our group innovatively used this ‘sleeping’ photophysical process to enhance the efficiency of fluorescent organic light-emitting diodes by simultaneously harvesting singlet and triplet excitons. Efforts are devoted to developing materials with high photoluminescence efficiency and effective RISC through appropriate molecular design in a series of donor–acceptor material systems. The experimental and theoretical results indicate that these materials exhibit hybridized local and charge-transfer excited state, which achieve a combination of the high radiation from local excited state and the high T m → S n ( m ≥2, n ≥1) conversion along charge-transfer excited state. As expected, the devices exhibited favourable external quantum efficiency and low roll-off, and especially an exciton utilization efficiency exceeding the limit of 25%. Considering the significant progress made in organic light-emitting diodes with this photophysical process, we review the relevant mechanism and material systems, as well as our design principle in materials and device application.

Dynamic adjustment of emission from both singlets and triplets: the role of excited state conformation relaxation and charge transfer in phenothiazine derivates

2021 ◽  
Author(s):  
Weidong Qiu ◽  
Xinyi Cai ◽  
Mengke Li ◽  
Liangying Wang ◽  
Yanmei He ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Dynamic Adjustment ◽  
Twisted Intramolecular Charge Transfer

Dynamic adjustment of emission behaviours by controlling the extent of twisted intramolecular charge transfer character in excited state.

Novel Carbazole-based Multifunctional Materials with Hybridized Local and Charge-Transfer Excited State Acting as Deep Blue Emitters and Phosphorescent Hosts for Highly Efficient Organic Light-Emitting Diodes

2021 ◽  
Author(s):  
Haitao Zhou ◽  
Mengna Yin ◽  
Zhenhong Zhao ◽  
Yanqin Miao ◽  
Xin Jin ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Multifunctional Materials ◽  
Light Emitting ◽  
Highly Efficient ◽  
Deep Blue ◽  
Organic Light ◽  
Blue Emitters

In this work, two carbazole- and benzo[d]oxazole-based novel multifunctional materials with hybridized local and charge-transfer (HLCT) characteristic, namely OCI and OCT, which could act as deep-blue fluorophors and phosphorescent hosts,...

scholarly journals Anion-enhanced excited state charge separation in a spiro-locked N-heterocycle-fused push-pull zinc porphyrin

2021 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Anuradha Liyanage ◽  
Ajyal Z. Alsaleh ◽  
Paul A. Karr ◽  
Jonathan P. Hill ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Charge Separation ◽  
Charge Transfer Complex ◽  
Zinc Porphyrin ◽  
New Type ◽  
State Charge

A new type of push–pull charge transfer complex, viz., a spiro-locked N-heterocycle-fused zinc porphyrin, ZnP-SQ, is shown to undergo excited state charge separation, which is enhanced by axial F− binding to the Zn center.

Charge Transfer States and Carrier Generation in 1D Organolead Iodide Semiconductors

2021 ◽  
Author(s):  
Eric Amerling ◽  
Yaxin Zhai ◽  
Bryon W. Larson ◽  
Yi Yao ◽  
Brian Fluegel ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Energy Harvesting ◽  
Metal Halide ◽  
Triplet Energy ◽  
Carrier Generation ◽  
Inorganic Components

Excited-state interactions between organic and inorganic components in hybrid metal halide semiconductors open up the possibility of moving charge and energy in deliberate ways, including energy funneling, triplet energy harvesting,...

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