High Efficiency Property of White OLED Doped on Blue Material and Red Material

Used as a blue emitter, fluorescent dye 4,4′-bis(9-ethyl-3-carbazovinylene)-1,1′-biphenyl (BCzVBi) is compounded with Bis[2-(2-hydroxyphenyl)-pyridine]beryllium(Bepp2) to yield high efficiency. When combined with green and red phosphorescent emitting layers, a broad band white light organic light-emitting diodes are obtained and studied. In this device, both singlet and triplet excitons can be harvested to generate white color. Through device structure optimization, a high efficiency of 20.8 cd/A, which corresponds to an external quantum efficiency of 11.3% has been achieved.

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P-221L: Late-News Poster: New Blue Phosphorescent Host for High-efficiency White OLED

SID Symposium Digest of Technical Papers ◽

10.1889/1.3621241 ◽

2011 ◽

Vol 42 (1) ◽

pp. 1787-1789 ◽

Cited By ~ 3

Author(s):

Jin-Sheng Lin ◽

Meng-Ting Lee ◽

Miao-Tsai Chu ◽

Mei-Rurng Tseng

Keyword(s):

High Efficiency ◽

Late News ◽

White Oled ◽

Blue Phosphorescent

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Illumination Control System and Drive Design of Large Power LED Lights

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.40 ◽

2011 ◽

Vol 335-336 ◽

pp. 40-43

Author(s):

Chun Hua Li ◽

Li Zhao ◽

Shan Hu ◽

Li Yun Shen

Keyword(s):

High Efficiency ◽

Power Converter ◽

Design Experiment ◽

Large Power ◽

Experiment Platform ◽

Arm Microprocessor ◽

Efficiency Property ◽

The Common ◽

Led Lights ◽

Driving Circuit

In view of the LED lights' high efficiency property, compared to the common driving circuit of large power LED, ARM microprocessor and Buck-Boost power converter are used to design the high efficiency LED lights' driving circuit. At the same time, PID adjustment mode is applied to realize Illumination control of the high efficiency LED lights, which improves the adjustable speed of the system and reduces the power loss. According the principle of design, experiment platform is rebuilt. Tests to the different kinds of lamps indicate that the driving is stable and realizes the Illumination setting and automatic Illumination adjustment.

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Quantum chemistry studies of meta-tetra(hydroxyphenyl)chlorin (mTHPC) and its isomers

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424614500205 ◽

2014 ◽

Vol 18 (06) ◽

pp. 465-470 ◽

Cited By ~ 1

Author(s):

Osmair Vital de Oliveira ◽

José Maria Pires

Keyword(s):

Excited State ◽

Quantum Chemistry ◽

High Efficiency ◽

Uv Spectra ◽

Chemical Hardness ◽

Triplet Excited State ◽

Efficiency Property ◽

Homo And Lumo ◽

Storage Energy ◽

Lipophilic Character

Quantum chemistry methods were used to study the meta-tetra(hydroxyphenyl)chlorin (mTHPC) and its isomers. The mTHPC (Foscan®) is a commercial chlorin, used in photodynamic therapy (PDT) and is classified as a second-generation drug in PDT. The present work is to obtain quantum chemistry properties which can explain the high efficiency of the mTHPC compared with its isomers (ortho and para) and other chlorins. Based in the chemical hardness and ionization potential obtained from HOMO and LUMO orbitals energy, our results show that all chlorins have similar reactivity. Moreover, all chlorins have approximately the same capacity to storage energy in the triplet excited state, with energy differences between the ground state and the triplet excited state of 1.38, 1.39 and 1.36 eV for oTHPC, mTHPC and pTHPC, respectively. The calculated UV spectra (a very important quantity which can be correlated with the photosensitizer (PS) efficiency property), shows that the present chlorins all have a peak at 622 nm. Finally, after analysis of the dipole moment differences, between the three isomers, an explanation about the greater mTHPC efficiency in PDT, was possible. Due to its greater lipophilic character, mTHPC is absorbed by tumor cells to a greater degree than oTHPC and pTHPC. Our findings are consistent with literature and can be used to help new drug design for use in PDT.

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Microcalorimeters for X-Ray Spectroscopy

International Astronomical Union Colloquium ◽

10.1017/s0252921100107365 ◽

1988 ◽

Vol 102 ◽

pp. 41

Author(s):

E. Silver ◽

C. Hailey ◽

S. Labov ◽

N. Madden ◽

D. Landis ◽

...

Keyword(s):

High Resolution ◽

High Efficiency ◽

Thermal Response ◽

Low Noise ◽

High Resolution Spectroscopy ◽

Superconducting Transition ◽

Sapphire Substrates ◽

Laboratory Plasmas ◽

Adiabatic Demagnetization ◽

Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

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Imaging and diffraction modes in Scanning Transmission Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144814 ◽

1986 ◽

Vol 44 ◽

pp. 684-687

Author(s):

J. M. Cowley ◽

R. Glaisher ◽

J. A. Lin ◽

H.-J. Ou

Keyword(s):

Scanning Transmission Electron Microscopy ◽

High Efficiency ◽

Fiber Optic ◽

Image Intensifier ◽

Detector System ◽

Detector Plane ◽

Secondary Electrons ◽

Transmission Electron ◽

Scanning Transmission ◽

Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

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Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118692 ◽

1985 ◽

Vol 43 ◽

pp. 364-365

Author(s):

K.M. Hones ◽

P. Sheldon ◽

B.G. Yacobi ◽

A. Mason

Keyword(s):

High Efficiency ◽

Lattice Mismatch ◽

Low Cost ◽

Growth Conditions ◽

Nonradiative Recombination ◽

Device Structure ◽

Si Substrates ◽

Transmission Electron ◽

Dislocation Densities ◽

Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

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