scholarly journals Photophysical and Electro-Optical Properties of Copolymers Bearing Blue and Red Chromophores for Single-Layer White OLEDs

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2629
Author(s):  
Despoina Tselekidou ◽  
Kyparisis Papadopoulos ◽  
Vasileios Kyriazopoulos ◽  
Konstantinos C. Andrikopoulos ◽  
Aikaterini K. Andreopoulou ◽  
...  
Keyword(s):  
White Light ◽  
Light Emission ◽  
Photophysical Properties ◽  
Single Layer ◽  
Visible Spectrum ◽  
Color Stability ◽  
Energy Transfer Mechanism ◽  
Molar Ratios ◽  
Polymeric Layer ◽  
Cie Coordinates

In this study, novel copolymers consisting of blue and red chromophores are presented to induce emission tuning, enabling the definition of white light emission in a single polymeric layer. These aromatic polyether sulfones exhibit high molecular weights, excellent solubility and processability via solution deposition techniques. In addition, by carefully controlling the molar ratios of chromophores composition, the energy transfer mechanism, from blue to red chromophores, takes place enabling us to define properly the emission covering the entire range of the visible spectrum. The optical and photophysical properties of the monomers and copolymers were thoroughly investigated via NIR-Vis-far UV Spectroscopic Ellipsometry (SE), Absorbance and Photoluminescence (PL). These copolymers are used as an emissive layer and applied in solution-processed WOLED devices. The fabricated WOLED devices have been subsequently studied and characterized in terms of their electroluminescence properties. Finally, the WOLED devices possess high color stability and demonstrate CIE Coordinates (0.33, 0.38), which approach closely the pure white light CIE coordinates.

Utilizing an effective framework to dye energy transfer in a carbazole-based metal–organic framework for high performance white light emission tuning

2018 ◽  
Vol 5 (11) ◽  
pp. 2868-2874 ◽  
Author(s):  
Yu-Pei Xia ◽  
Chen-Xue Wang ◽  
Lian-Cai An ◽  
Da-Shuai Zhang ◽  
Tong-Liang Hu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
White Light ◽  
High Performance ◽  
Light Emission ◽  
Metal Organic Framework ◽  
White Light Emission ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Light Emitting ◽  
Metal Organic

By introducing dyes into a MOF, a white-light-emitting luminophor was obtained based on effective framework to dye energy transfer mechanism.

scholarly journals A novel donor–π–acceptor halochromic 2,6-distyrylnaphthalene chromophore: synthesis, photophysical properties and DFT studies

RSC Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 168-176
Author(s):  
Farhad Panahi ◽  
Ali Mahmoodi ◽  
Sajjad Ghodrati ◽  
Fazlolah Eshghi
Keyword(s):  
White Light ◽  
Potential Application ◽  
High Performance ◽  
Light Emission ◽  
Photophysical Properties ◽  
White Light Emission ◽  
High Potential ◽  
Dft Studies ◽  
Ph Responsive

A new pH-responsive fluorescence chromophore with white light emission at pH = 3 was synthesized which has high potential application in the preparation of high-performance lighting devices.

scholarly journals Secondary Through-Space Interactions: Achieving Single-Molecule White-Light Emission from Clusteroluminogens with Isolated Phenyl Rings

2022 ◽  
Author(s):  
Jianyu Zhang ◽  
Parvej Alam ◽  
Siwei Zhang ◽  
Hanchen Shen ◽  
Lianrui Hu ◽  
...  
Keyword(s):  
Single Molecule ◽  
White Light ◽  
Light Emission ◽  
Photophysical Properties ◽  
White Light Emission ◽  
Excitation Wavelength ◽  
Conjugated Molecules ◽  
Long Wavelength ◽  
Phenyl Rings ◽  
Donor Acceptor

Clusteroluminogens (CLgens) refer to some non-conjugated molecules that show visible light due to the formation of aggregates and unique electronic properties with through-space interactions (TSI). Although mature and systematic theories of molecular photophysics have been developed to study conventional conjugated chromophores, it is still challenging to endow CLgens with designed photophysical properties by manipulating TSI. Herein, three CLgens with non-conjugated donor-acceptor structures and different halide substituents with secondary TSI are designed and synthesized. These molecules show multiple emissions and even white-light emission in the crystalline state and the intensity ratio of these multiple emission peaks is easily manipulated by changing the halide atom and excitation wavelength. Experimental and theoretical results successfully disclose the electronic nature of these multiple emissions: through-space conjugation for short-wavelength fluorescence, through-space charge transfer based on secondary TSI for long-wavelength fluorescence, and room-temperature phosphorescence. The introduction of secondary TSI to CLgens not only enriches their varieties of photophysical properties but also inspires the establishment of novel aggregate photophysics for clusteroluminescence.

Eu3+/Eu2+/Tb3+ co-activated single-phase Gd2O2S: A high-performance white light emitting phosphor for light emitting diode

2021 ◽  
Vol 11 (1) ◽  
pp. 54-62
Author(s):  
Jinpeng Xie ◽  
Bonan Liu ◽  
Qingtao Qong ◽  
Zhicheng Xu ◽  
Zhiqiang Jin ◽  
...  
Keyword(s):  
White Light ◽  
High Performance ◽  
Single Phase ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Energy Transfer Mechanism ◽  
Excitation Spectra ◽  
Phosphor Material ◽  
Light Emitting ◽  
Co Doped

In this work, we report Eu3+/Tb3+/Eu2+ co-activated Gd2O2 S as novel phosphor materials that can be effectively applied in the white-light emitting diode based on a near-UV chip with sensational performances. The luminescent properties and energy transfer mechanism have been thoroughly investigated. The as-prepared europium/terbium co-doped Gd2O2 S phosphors exhibit strong fluorescence with tunable color output under UV-vis light excitation. Furthermore, a high response to ultraviolet illumination of 398 nm wavelength was observed in the excitation spectra, indicating an excellent match with a light-emitting-diode chip in the dominant emissions. It is found that a tricolor (blue, green and red) emission band which results in a white light emission can be acquired when Eu3+, Eu2+ and Tb3+ ions are all co-doped into the single phase Gd2O2S, and an optimum ion doping level (10 at.% Eu and 0.7 at.% Tb) can effectively emit nearly pure white color photoluminescence with lifetime effectively tuned from 0.55 ms to 1.10 ms. The CIE (Commission International de I'Eclairage 1931 chromaticity) is X = 0.3507, Y = 0.3029. It is therefore expected that the newly found phosphor material with high-performance properties possess great potentials for the future advanced white LED applications.

White light emission from two blue emitters of an equimolar (1:1) blend in single-layer device

2005 ◽  
Vol 150 (2) ◽  
pp. 189-193 ◽  
Author(s):  
O.-K. Kim ◽  
W.H. Kim ◽  
Z. Huang ◽  
J.T. Je ◽  
C.S.P. Sung
Keyword(s):  
White Light ◽  
Light Emission ◽  
Single Layer ◽  
White Light Emission ◽  
Blue Emitters
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