scholarly journals Thermochemically Stable Liquid-Crystalline Gold(I) Complexes Showing Enhanced Room Temperature Phosphorescence

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 227 ◽  
Author(s):  
Yuki Kuroda ◽  
Shin-ya Nakamura ◽  
Katam Srinivas ◽  
Arruri Sathyanarayana ◽  
Ganesan Prabusankar ◽  
...  

Gold(I) complexes are some of the most attractive materials for generating aggregation-induced emission (AIE), enabling the realization of novel light-emitting applications such as chemo-sensors, bio-sensors, cell imaging, and organic light-emitting diodes (OLEDs). In this study, we propose a rational design of luminescent gold complexes to achieve both high thermochemical stability and intense room temperature phosphorescence, which are desirable features in practical luminescent applications. Here, a series of gold(I) complexes with ligands of N-heterocyclic carbene (NHC) derivatives and/or acetylide were synthesized. Detailed characterization revealed that the incorporation of NHC ligands could increase the molecular thermochemical stability, as the decomposition temperature was increased to ~300 °C. We demonstrate that incorporation of both NHC and acetylide ligands enables us to generate gold(I) complexes exhibiting both high thermochemical stability and high room-temperature phosphorescence quantum yield (>40%) under ambient conditions. Furthermore, we modified the length of alkoxy chains at ligands, and succeeded in synthesizing a liquid crystalline gold(I) complex while maintaining the relatively high thermochemical stability and quantum yield.

2020 ◽  
Vol 8 (19) ◽  
pp. 6552-6557 ◽  
Author(s):  
Raquel Giménez ◽  
Olga Crespo ◽  
Beatriz Diosdado ◽  
Anabel Elduque

Phosphorescence in the liquid crystal state with one of the highest quantum yield values, 42%, at room temperature is reported.


2020 ◽  
Author(s):  
Yunzhong Wang ◽  
Saixing Tang ◽  
Yating Wen ◽  
Shuyuan Zheng ◽  
Bing Yang ◽  
...  

<div>Persistent room-temperature phosphorescence (p-RTP) from pure organics is attractive </div><div>due to its fundamental importance and potential applications in molecular imaging, </div><div>sensing, encryption, anticounterfeiting, etc.1-4 Recently, efforts have been also made in </div><div>obtaining color-tunable p-RTP in aromatic phosphors5 and nonconjugated polymers6,7. </div><div>The origin of color-tunable p-RTP and the rational design of such luminogens, </div><div>particularly those with explicit structure and molecular packing, remain challenging. </div><div>Noteworthily, nonconventional luminophores without significant conjugations generally </div><div>possess excitation-dependent photoluminescence (PL) because of the coexistence of </div><div>diverse clustered chromophores6,8, which strongly implicates the possibility to achieve </div><div>color-tunable p-RTP from their molecular crystals assisted by effective intermolecular </div><div>interactions. Here, inspirited by the highly stable double-helix structure and multiple </div><div>hydrogen bonds in DNA, we reported a series of nonconventional luminophores based on </div><div>hydantoin (HA), which demonstrate excitation-dependent PL and color-tunable p-RTP </div><div>from sky-blue to yellowish-green, accompanying unprecedentedly high PL and p-RTP </div><div>efficiencies of up to 87.5% and 21.8%, respectively. Meanwhile, the p-RTP emissions are </div><div>resistant to vigorous mechanical grinding, with lifetimes of up to 1.74 s. Such robust, </div><div>color-tunable and highly efficient p-RTP render the luminophores promising for varying </div><div>applications. These findings provide mechanism insights into the origin of color-tunable </div><div>p-RTP, and surely advance the exploitation of efficient nonconventional luminophores.</div>


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
So Yeong Jeong ◽  
Hye Rin Shim ◽  
Yunha Na ◽  
Ki Suk Kang ◽  
Yongmin Jeon ◽  
...  

AbstractWearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited a stable operating lifetime under ambient conditions, enough mechanical durability to endure the deformation by the movement of humans, and washability for maintaining its optoelectronic properties even in water condition such as rain, sweat, or washing. In this study, the main technology used to realize this textile-based OLED was multi-functional near-room-temperature encapsulation. The outstanding impermeability of TiO2 film deposited at near-room-temperature was demonstrated. The internal residual stress in the encapsulation layer was controlled, and the device was capped by highly cross-linked hydrophobic polymer film, providing a highly impermeable, mechanically flexible, and waterproof encapsulation.


Nanoscale ◽  
2021 ◽  
Author(s):  
Dongdong Yan ◽  
Qionghua Mo ◽  
Shuangyi Zhao ◽  
Wensi Cai ◽  
Zhigang Zang

With a high photoluminescence quantum yield (PLQY) being able to exceed 90% for those prepared by hot injection method, CsPbBr3 quantum dots (QDs) have attracted intensive attentions for white light-emitting...


2021 ◽  
Author(s):  
Takumi Hosono ◽  
Nicolas Oliveira Decarli ◽  
Paola Zimmermann Crocomo ◽  
Tsuyoshi Goya ◽  
Leonardo Evaristo de Sousa ◽  
...  

Exploring design principle for switching thermally activated dealyed fluorescecne (TADF) and room temperature phosphorescence (RTP) is a fundamentally imporant research in developing triplet-mediated photofunctional organic materials. Herein systematic studies on the regioisomeric and substituents effects in a twisted donor–acceptor–donor (D–A–D) scaffold (A = dibenzo[a,j]phenazine; D = dihydrophenazasiline) on the fate of the excited state have been performed. The study revealed that the regiosiomerism clearly affects the emission behavior of the D–A–D compounds. Distinct difference in TADF, dual TADF & RTP, and dual RTP were observed, depending on the host used. Furthermore, OLED organic light-emitting diodes (OLEDs) fabricated with the developed emitters achieved high external quantum yields for RTP-based OLEDS up to 7.4%.


Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ye Tao ◽  
Lele Tang ◽  
Qi Wei ◽  
Jibiao Jin ◽  
Wenbo Hu ◽  
...  

Organic ultralong room-temperature phosphorescence (OURTP) with a long-lived triplet excited state up to several seconds has triggered widespread research interests, but most OURTP materials are excited by only ultraviolet (UV) or blue light owing to their unique stabilized triplet- and solid-state emission feature. Here, we demonstrate that near-infrared- (NIR-) excitable OURTP molecules can be rationally designed by implanting intra/intermolecular charge transfer (CT) characteristics into H-aggregation to stimulate the efficient nonlinear multiphoton absorption (MPA). The resultant upconverted MPA-OURTP show ultralong lifetimes over 0.42 s and a phosphorescence quantum yield of ~37% under both UV and NIR light irradiation. Empowered by the extraordinary MPA-OURTP, novel applications including two-photon bioimaging, visual laser power detection and excitation, and lifetime multiplexing encryption devices were successfully realized. These discoveries illustrate not only a delicate design map for the construction of NIR-excitable OURTP materials but also insightful guidance for exploring OURTP-based nonlinear optoelectronic properties and applications.


2020 ◽  
Vol 8 (22) ◽  
pp. 7330-7335 ◽  
Author(s):  
Zheng-Fei Liu ◽  
Xue Chen ◽  
Wei Jun Jin

The phosphoramidic acid oligomer as an organic non-conjugated RTP system is proposed. The new system not only has ultralong phosphorescence lifetime up to 777 ms and high quantum yield, but also displays dual-band optical waveguide behavior.


2019 ◽  
Vol 10 (31) ◽  
pp. 7352-7357 ◽  
Author(s):  
Zhu Mao ◽  
Zhan Yang ◽  
Chao Xu ◽  
Zongliang Xie ◽  
Long Jiang ◽  
...  

Small energy gap boosts dual-channel triplet harvesting via TADF and UOP, which suppresses long-lived triplet concentration quenching. An infrared laser (808 nm) is able to induce persistent emission under ambient conditions.


2018 ◽  
Vol 17 (5) ◽  
pp. 622-627 ◽  
Author(s):  
Toshiko Mizokuro ◽  
Aizitiaili Abulikemu ◽  
Yusuke Sakagami ◽  
Tetsuro Jin ◽  
Kenji Kamada

Room-temperature phosphorescence of a Pt-porphyrin derivative was enhanced in quantum yield and lifetime by fixing it on the surface of nanometer-scale pores of porous glass.


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