TCL Corporate Research

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China
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Xu B.,Guangdong University of Technology | Xu B.,Sun Yat Sen University | He J.,Guangdong University of Technology | Mu Y.,Guangdong University of Technology | And 10 more authors.
Chemical Science | Year: 2015

Organic materials exhibiting mechanoluminescence (ML) are promising for usage in displays, lighting and sensing. However, the mechanism for ML generation remains unclear, and the light-emitting performance of organic ML materials in the solid state has been severely limited by an aggregation-caused quenching (ACQ) effect. Herein, we present two strongly photoluminescent polymorphs (i.e., Cg and Cb) with distinctly different ML activities based on a tetraphenylethene derivative P4TA. As an aggregation-induced emission (AIE) emitter, P4TA perfectly surmounted the ACQ, making the resultant block-like crystals in the Cg phase exhibit brilliant green ML under daylight at room temperature. The ML-inactive prism-like crystals Cb can also have their ML turned on by transitioning toward Cg with the aid of dichloromethane vapor. Moreover, the Cg polymorph shows ML and mechanochromism simultaneously and respectively without and with UV irradiation under a force stimulus, thus suggesting a feasible design direction for the development of efficient and multifunctional ML materials. © The Royal Society of Chemistry 2015.


Mao Z.,Sun Yat Sen University | Yang Z.,Sun Yat Sen University | Mu Y.,Sun Yat Sen University | Zhang Y.,Sun Yat Sen University | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2015

Organic mechanoluminochromic materials are mechano/piezo-responsive and promising for applications in sensors, displays, and data storage devices. However, their switching range of emission is seriously impeded by only one kind of emission (either a fluorescent or phosphorescent peak) in the spectrum of single organic compounds. This study presents a design strategy for pure organic compounds with excellent roomerature fluorescent-phosphorescent dual-emission (rFPDE) properties, which combines the effective factors of dipenylsulfone group, crystalline state, and heavy atom effect. Following the principle of color mixing, myriad emission colors with a wide range from orange to purple and across white zone in a straight line in the chromaticity diagram of the Commission Internationale de l'Eclairage (CIE) can be obtained by simply mechanical grinding the compound. The unique properties could be concentrated on a pure organic compound through this design strategy, which provides a new efficient channel for the discovery of efficient mechano-responsive organic materials. Grinding a rainbow: A purely organic compound with excellent roomerature fluorescent-phosphorescent dual-emission (rFPDE) properties brought about by mechanical grinding has been demonstrated. It shows linearly tunable emission colors with a straight line across the white zone in the chromaticity diagram, following the principle of color mixing. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Xu S.,Sun Yat Sen University | Liu T.,Sun Yat Sen University | Mu Y.,Sun Yat Sen University | Wang Y.-F.,Shenzhen China Star Optoelectronics Technology Co. | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2015

Compounds displaying delayed fluorescence (DF), from severe concentration quenching, have limited applications as nondoped organic light-emitting diodes and material sciences. As a nondoped fluorescent emitter, aggregation-induced emission (AIE) materials show high emission efficiency in their aggregated states. Reported herein is an AIE-active, DF compound in which the molecular interaction is modulated, thereby promoting triplet harvesting in the solid state with a high photoluminescence quantum yield of 93.3%, which is the highest quantum yield, to the best of our knowledge, for long-lifetime emitters. Simultaneously, the compound with asymmetric molecular structure exhibited strong mechanoluminescence (ML) without pretreatment in the solid state, thus exploiting a design and synthetic strategy to integrate the features of DF, AIE, and ML into one compound. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.


PubMed | TCL Corporate Research, Sun Yat Sen University and Shenzhen China Star Optoelectronics Technology Co.
Type: Journal Article | Journal: Angewandte Chemie (International ed. in English) | Year: 2015

Organic mechanoluminochromic materials are mechano/piezo-responsive and promising for applications in sensors, displays, and data storage devices. However, their switching range of emission is seriously impeded by only one kind of emission (either a fluorescent or phosphorescent peak) in the spectrum of single organic compounds. This study presents a design strategy for pure organic compounds with excellent room-temperature fluorescent-phosphorescent dual-emission (rFPDE) properties, which combines the effective factors of dipenylsulfone group, crystalline state, and heavy atom effect. Following the principle of color mixing, myriad emission colors with a wide range from orange to purple and across white zone in a straight line in the chromaticity diagram of the Commission Internationale de lEclairage (CIE) can be obtained by simply mechanical grinding the compound. The unique properties could be concentrated on a pure organic compound through this design strategy, which provides a new efficient channel for the discovery of efficient mechano-responsive organic materials.


Mao Z.,Sun Yat Sen University | Yang Z.,Sun Yat Sen University | Mu Y.,Sun Yat Sen University | Zhang Y.,Sun Yat Sen University | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2015

Organic mechanoluminochromic materials are mechano/piezo-responsive and promising for applications in sensors, displays, and data storage devices. However, their switching range of emission is seriously impeded by only one kind of emission (either a fluorescent or phosphorescent peak) in the spectrum of single organic compounds. This study presents a design strategy for pure organic compounds with excellent roomerature fluorescent-phosphorescent dual-emission (rFPDE) properties, which combines the effective factors of dipenylsulfone group, crystalline state, and heavy atom effect. Following the principle of color mixing, myriad emission colors with a wide range from orange to purple and across white zone in a straight line in the chromaticity diagram of the Commission Internationale de l'Eclairage (CIE) can be obtained by simply mechanical grinding the compound. The unique properties could be concentrated on a pure organic compound through this design strategy, which provides a new efficient channel for the discovery of efficient mechano-responsive organic materials. Grinding a rainbow: A purely organic compound with excellent roomerature fluorescent-phosphorescent dual-emission (rFPDE) properties brought about by mechanical grinding has been demonstrated. It shows linearly tunable emission colors with a straight line across the white zone in the chromaticity diagram, following the principle of color mixing. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li X.-L.,South China University of Technology | Ye H.,South China University of Technology | Chen D.-C.,South China University of Technology | Liu K.-K.,South China University of Technology | And 7 more authors.
Israel Journal of Chemistry | Year: 2014

A series of triazole and pyridine hybrid molecules, with a triazole core and pyridine periphery, were designed and synthesized as an electron-transport layer (ETL) and a hole/exciton-block layer for green phosphorescent organic light-emitting diodes. Compared with the widely-used electron-transport material (ETM) of 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ) with a triazole core, lower-lying HOMO and LUMO energy levels were obtained with the introduction of pyridine rings onto the periphery of the molecules, giving improved electron injection and carrier confinement. Significantly reduced driving voltages were achieved in a device structure of ITO/HATCN (5 nm)/TAPC (40 nm)/CBP:8 wt % Ir(PPy)3 (10 nm)/ETL (40 nm)/LiF (1 nm)/Al (90 nm), giving a maximum power efficiency of 72.2 lm W -1 and an external quantum efficiency of 21.8 %, due to the improved electron injection and transport and thus, more balanced carrier recombination, which are much higher than those of the device based on TAZ. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Ye H.,South China University of Technology | Chen D.,South China University of Technology | Liu M.,South China University of Technology | Su S.-J.,South China University of Technology | And 4 more authors.
Advanced Functional Materials | Year: 2014

A series of pyridine-containing electron-transport materials are developed as an electron-transport layer for the FIrpic-based blue phosphorescent organic light-emitting diodes. Their energy levels can be tuned by the introduction of pyridine rings in the framework and on the periphery of the molecules. Significantly reduced operating voltage is achieved without compromising external quantum efficiency by solely tuning the nitrogen atom orientations of those pyidine rings. Unprecedented low operating voltages of 2.61 and 3.03 V are realized at 1 and 100 cd m-2, giving ever highest power efficiency values of 65.8 and 59.7 lm W-1, respectively. In addition, the operating voltages at 100 cd m-2 can be further reduced to 2.70 V by using a host material with a small singlet-triplet exchange energy, and the threshold voltage for electroluminescence can even be 0.2-0.3 V lower than the theoretical minimum value of the photon energy divided by electron charge. Aside from the reduced operating voltage, a further reduced roll-off in efficiency is also achieved by the combination of an appropriate host material. Unprecedented low operating voltages are realized for the FIrpic-based blue phosphorescent OLEDs by using pyridine-containing electron-transport materials, giving ever highest power efficiencies of 65.8 and 59.7 lm W-1 at 1 and 100 cd m-2, respectively. The threshold voltage for electroluminescence can be 0.2-0.3 V lower than the minimum value of hv/e by using a host material with low ΔEST. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li Y.,South China University of Technology | Wang Z.,South China University of Technology | Li X.,South China University of Technology | Xie G.,South China University of Technology | And 7 more authors.
Chemistry of Materials | Year: 2015

A series of blue emitters incorporating spiro[fluorene-9,9-thioxanthene] or spiro[fluorene-9,9-thioxanthene-S,S-dioxide] as the core and phenylcarbazole or triphenylamine as the arms were designed and synthesized. Their spiro conformation is beneficial for their thermal stability and for reducing the trend of aggregation quenching. By tuning the valence of the sulfur atom, highly efficient local excited (LE) state deep blue emitters and charge-transfer (CT) state blue emitters are obtained. The devices based on the LE emitters TPA-S and CzB-S as the nondoped emissive layer exhibit high external quantum efficiency of 1.76% and 2.03% and Commission Internationale de lEclairage (CIE) coordinates of (0.158, 0.039) and (0.160, 0.054), respectively, and their CIEy values are among the smallest ever reported for the deep blue OLEDs and are readily very close to that of the inorganic light-emitting diode [CIE (0.16, 0.02)]. The nondoped device based on the CT emitter TPA-SO2 as the emissive layer also exhibits a high current efficiency of 5.46 cd A-1 and CIE coordinates of (0.154, 0.168). To fully utilize the 25% singlet and 75% triplet excitons, fluorescent/phosphorescent hybrid white organic light-emitting diodes in a single-emissive-layer architecture were also fabricated with TPA-SO2 as the blue emitter as well as the host of orange phosphorescent emitter to give forward-viewing power efficiency of 47.9 lm W-1, which is the highest value ever reported for the devices in a similar architecture without using any out-coupling technology. © 2015 American Chemical Society.


Zhu R.,University of Central Florida | Xu S.,University of Central Florida | Hong Q.,University of Central Florida | Wu S.-T.,University of Central Florida | And 4 more authors.
Applied Optics | Year: 2014

A two-dimensional/three-dimensional (2D/3D) display system is presented based on a twisted-nematic cell integrated polymeric microlens array. This device structure has the advantages of fast response time and low operation voltage. The crosstalk of the system is analyzed in detail and two approaches are proposed to reduce the crosstalk: a double lens system and the prism approach. Illuminance distribution analysis proves these two approaches can dramatically reduce crosstalk, thus improving image quality. © 2014 Optical Society of America.


Tang W.,TCL Corporate Research | Yan X.,TCL Corporate Research
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

This paper presents a real-time efficient glass-free 3D system, which is based on FPGA. The system converts two-view input that is 60 frames per second (fps) 1080P stream into a multi-view video with 30fps and 4K resolution. In order to provide smooth and comfortable viewing experience, glass-free 3D systems must display multi-view videos. To generate a multi-view video from a two-view input includes three steps, the first is to compute disparity maps from two input views; the second is to synthesize a couple of new views based on the computed disparity maps and input views; the last is to produce video from the new views according to the specifications of the lens installed on TV sets. © 2016 SPIE.

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