The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
J. G. Eden - One of the best experts on this subject based on the ideXlab platform.
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fragmentation and emission of POPOP and coumarin dye vapor in an ultraviolet preionized transverse discharge
Journal of Applied Physics, 1994Co-Authors: R. W. Herrick, R. D. Fraser, J. G. EdenAbstract:Intense, streamer‐free discharges have been produced in POPOP (1,4‐di[2‐(5‐phenyloxazolyl)]‐ benzene), α‐NPO (2‐(α‐naphthyl)‐5‐phenyl‐oxazole), PBBO (2‐(4‐biphenylyl)‐6‐ phenylbenzoxazol‐1,3), and coumarin dye vapors buffered in He or rare gas/N2 mixtures. The transverse discharge has an equivalent series inductance of ∼85 nH, a current rise time of ∼50 ns, a pulse width (FWHM) of ∼140 ns, and active lengths up to 50 cm. For specific power loadings of rare gas/POPOP vapor mixtures ranging from 2 to ∼11 MW cm−3, the wavelength‐integrated fluorescence falls to 50% of its initial value after 150–200 shots (at ∼620 K) and emission bands of CN and C2 appear. Under comparable conditions, the fluorescence efficiency of α‐NPO is only 40% of that for POPOP vapor. The coumarin dyes are considerably less stable than POPOP and strong fluorescence on the Swan bands of C2 is observed after only a few shots. Net optical loss is measured when Ne/N2/POPOP vapor discharges are probed with a dye laser at ∼400 nm.
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Fragmentation and emission of POPOP and coumarin dye vapor in an ultraviolet‐preionized, transverse discharge
Journal of Applied Physics, 1994Co-Authors: R. W. Herrick, R. D. Fraser, J. G. EdenAbstract:Intense, streamer‐free discharges have been produced in POPOP (1,4‐di[2‐(5‐phenyloxazolyl)]‐ benzene), α‐NPO (2‐(α‐naphthyl)‐5‐phenyl‐oxazole), PBBO (2‐(4‐biphenylyl)‐6‐ phenylbenzoxazol‐1,3), and coumarin dye vapors buffered in He or rare gas/N2 mixtures. The transverse discharge has an equivalent series inductance of ∼85 nH, a current rise time of ∼50 ns, a pulse width (FWHM) of ∼140 ns, and active lengths up to 50 cm. For specific power loadings of rare gas/POPOP vapor mixtures ranging from 2 to ∼11 MW cm−3, the wavelength‐integrated fluorescence falls to 50% of its initial value after 150–200 shots (at ∼620 K) and emission bands of CN and C2 appear. Under comparable conditions, the fluorescence efficiency of α‐NPO is only 40% of that for POPOP vapor. The coumarin dyes are considerably less stable than POPOP and strong fluorescence on the Swan bands of C2 is observed after only a few shots. Net optical loss is measured when Ne/N2/POPOP vapor discharges are probed with a dye laser at ∼400 nm.
R. W. Herrick - One of the best experts on this subject based on the ideXlab platform.
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fragmentation and emission of POPOP and coumarin dye vapor in an ultraviolet preionized transverse discharge
Journal of Applied Physics, 1994Co-Authors: R. W. Herrick, R. D. Fraser, J. G. EdenAbstract:Intense, streamer‐free discharges have been produced in POPOP (1,4‐di[2‐(5‐phenyloxazolyl)]‐ benzene), α‐NPO (2‐(α‐naphthyl)‐5‐phenyl‐oxazole), PBBO (2‐(4‐biphenylyl)‐6‐ phenylbenzoxazol‐1,3), and coumarin dye vapors buffered in He or rare gas/N2 mixtures. The transverse discharge has an equivalent series inductance of ∼85 nH, a current rise time of ∼50 ns, a pulse width (FWHM) of ∼140 ns, and active lengths up to 50 cm. For specific power loadings of rare gas/POPOP vapor mixtures ranging from 2 to ∼11 MW cm−3, the wavelength‐integrated fluorescence falls to 50% of its initial value after 150–200 shots (at ∼620 K) and emission bands of CN and C2 appear. Under comparable conditions, the fluorescence efficiency of α‐NPO is only 40% of that for POPOP vapor. The coumarin dyes are considerably less stable than POPOP and strong fluorescence on the Swan bands of C2 is observed after only a few shots. Net optical loss is measured when Ne/N2/POPOP vapor discharges are probed with a dye laser at ∼400 nm.
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Fragmentation and emission of POPOP and coumarin dye vapor in an ultraviolet‐preionized, transverse discharge
Journal of Applied Physics, 1994Co-Authors: R. W. Herrick, R. D. Fraser, J. G. EdenAbstract:Intense, streamer‐free discharges have been produced in POPOP (1,4‐di[2‐(5‐phenyloxazolyl)]‐ benzene), α‐NPO (2‐(α‐naphthyl)‐5‐phenyl‐oxazole), PBBO (2‐(4‐biphenylyl)‐6‐ phenylbenzoxazol‐1,3), and coumarin dye vapors buffered in He or rare gas/N2 mixtures. The transverse discharge has an equivalent series inductance of ∼85 nH, a current rise time of ∼50 ns, a pulse width (FWHM) of ∼140 ns, and active lengths up to 50 cm. For specific power loadings of rare gas/POPOP vapor mixtures ranging from 2 to ∼11 MW cm−3, the wavelength‐integrated fluorescence falls to 50% of its initial value after 150–200 shots (at ∼620 K) and emission bands of CN and C2 appear. Under comparable conditions, the fluorescence efficiency of α‐NPO is only 40% of that for POPOP vapor. The coumarin dyes are considerably less stable than POPOP and strong fluorescence on the Swan bands of C2 is observed after only a few shots. Net optical loss is measured when Ne/N2/POPOP vapor discharges are probed with a dye laser at ∼400 nm.
A. K. Dutta - One of the best experts on this subject based on the ideXlab platform.
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spectroscopic study of nonamphiphilic 2 2 p phenylenebis 5 phenyloxazol POPOP assembled in supramolecular langmuir blodgett films
Journal of Physical Chemistry B, 1997Co-Authors: A. K. DuttaAbstract:This paper reports the incorporation of a nonamphiphilic blue laser dye 2,2‘-p-phenylenebis(5-phenyloxazol), abbreviated as POPOP, in Langmuir−Blodgett (LB) films mixed with stearic acid (SA) and their spectroscopic properties. The surface pressure versus area per molecule isotherms of POPOP mixed with SA at different molar ratios reveal a plateau-like region that suggests reorientation of the POPOP molecules from lying flat at the air−water interface to an almost vertical alignment. Miscibility studies indicate a repulsive type of interaction between the components in the mixture, resulting in the formation of microcrystallites in the LB films that is confirmed by spectroscopic studies. Perhaps the most interesting feature of this study is the appearance of a new band at about 400 nm in absorption spectra of the mixed LB film of POPOP and SA that is assigned to a low-lying hidden 1Lb state. The appearance of the same band in a mixture of ethanol and water with the volume fraction of water in the mixture ...
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Spectroscopic Study of Nonamphiphilic 2,2‘-p-Phenylenebis(5-phenyloxazol) (POPOP) Assembled in Supramolecular Langmuir−Blodgett Films
The Journal of Physical Chemistry B, 1997Co-Authors: A. K. DuttaAbstract:This paper reports the incorporation of a nonamphiphilic blue laser dye 2,2‘-p-phenylenebis(5-phenyloxazol), abbreviated as POPOP, in Langmuir−Blodgett (LB) films mixed with stearic acid (SA) and their spectroscopic properties. The surface pressure versus area per molecule isotherms of POPOP mixed with SA at different molar ratios reveal a plateau-like region that suggests reorientation of the POPOP molecules from lying flat at the air−water interface to an almost vertical alignment. Miscibility studies indicate a repulsive type of interaction between the components in the mixture, resulting in the formation of microcrystallites in the LB films that is confirmed by spectroscopic studies. Perhaps the most interesting feature of this study is the appearance of a new band at about 400 nm in absorption spectra of the mixed LB film of POPOP and SA that is assigned to a low-lying hidden 1Lb state. The appearance of the same band in a mixture of ethanol and water with the volume fraction of water in the mixture ...
R. D. Fraser - One of the best experts on this subject based on the ideXlab platform.
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fragmentation and emission of POPOP and coumarin dye vapor in an ultraviolet preionized transverse discharge
Journal of Applied Physics, 1994Co-Authors: R. W. Herrick, R. D. Fraser, J. G. EdenAbstract:Intense, streamer‐free discharges have been produced in POPOP (1,4‐di[2‐(5‐phenyloxazolyl)]‐ benzene), α‐NPO (2‐(α‐naphthyl)‐5‐phenyl‐oxazole), PBBO (2‐(4‐biphenylyl)‐6‐ phenylbenzoxazol‐1,3), and coumarin dye vapors buffered in He or rare gas/N2 mixtures. The transverse discharge has an equivalent series inductance of ∼85 nH, a current rise time of ∼50 ns, a pulse width (FWHM) of ∼140 ns, and active lengths up to 50 cm. For specific power loadings of rare gas/POPOP vapor mixtures ranging from 2 to ∼11 MW cm−3, the wavelength‐integrated fluorescence falls to 50% of its initial value after 150–200 shots (at ∼620 K) and emission bands of CN and C2 appear. Under comparable conditions, the fluorescence efficiency of α‐NPO is only 40% of that for POPOP vapor. The coumarin dyes are considerably less stable than POPOP and strong fluorescence on the Swan bands of C2 is observed after only a few shots. Net optical loss is measured when Ne/N2/POPOP vapor discharges are probed with a dye laser at ∼400 nm.
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Fragmentation and emission of POPOP and coumarin dye vapor in an ultraviolet‐preionized, transverse discharge
Journal of Applied Physics, 1994Co-Authors: R. W. Herrick, R. D. Fraser, J. G. EdenAbstract:Intense, streamer‐free discharges have been produced in POPOP (1,4‐di[2‐(5‐phenyloxazolyl)]‐ benzene), α‐NPO (2‐(α‐naphthyl)‐5‐phenyl‐oxazole), PBBO (2‐(4‐biphenylyl)‐6‐ phenylbenzoxazol‐1,3), and coumarin dye vapors buffered in He or rare gas/N2 mixtures. The transverse discharge has an equivalent series inductance of ∼85 nH, a current rise time of ∼50 ns, a pulse width (FWHM) of ∼140 ns, and active lengths up to 50 cm. For specific power loadings of rare gas/POPOP vapor mixtures ranging from 2 to ∼11 MW cm−3, the wavelength‐integrated fluorescence falls to 50% of its initial value after 150–200 shots (at ∼620 K) and emission bands of CN and C2 appear. Under comparable conditions, the fluorescence efficiency of α‐NPO is only 40% of that for POPOP vapor. The coumarin dyes are considerably less stable than POPOP and strong fluorescence on the Swan bands of C2 is observed after only a few shots. Net optical loss is measured when Ne/N2/POPOP vapor discharges are probed with a dye laser at ∼400 nm.
Chandran Sudakar - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Cu-Deficient and Zn-Graded Cu–In–Zn–S Quantum Dots and Hybrid Inorganic–Organic Nanophosphor Composite for White Light Emission
ACS applied materials & interfaces, 2016Co-Authors: P. Ilaiyaraja, Pavana S. V. Mocherla, T. K. Srinivasan, Chandran SudakarAbstract:Cu-deficient graded-zinc Cu-In-Zn-S (CIZS) quantum dots (QDs) were synthesized by a two-step solvothermal method. These CIZS QDs exhibited size and composition tunable photoluminescence characteristics with emission color tunable from greenish-yellow to orange to red with a relatively high quantum yield between 45 and 60%. Novel white-light-emitting (WLE) hybrid composite is fabricated by integrating the blue-emissive 1,4-bis-2-(5-phenyl oxazolyl)-benzene (POPOP) organic fluorophore and quaternary CIZS inorganic QDs. Integrating CIZS QDs with POPOP fluorophore resulted in series of tunable emission colors with CIE coordinates lying in a straight line between the coordinates of the end member. WLE was shown for hybrid mixture comprising 0.5 nM of POPOP and 3 mg/mL of CIZS QDs with color coordinates (0.3312, 0.3324). Thin films of this hybrid mixture in PMMA matrix coated on UV-LED or on glass substrates with UV backlit light also showed broadband WLE with ideal CIE color coordinates of (0.34, 0.33), high color-rendering index value of 92, and correlated color temperature value of 5143 K. The hybrid composite exhibit Forster resonance energy transfer cascading from POPOP to CIZS which results in emission covering the entire visible spectral range. POPOP and CIZS QDs hybrid composite is a versatile material for WLED applications.
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Synthesis of Cu-Deficient and Zn-Graded Cu–In–Zn–S Quantum Dots and Hybrid Inorganic–Organic Nanophosphor Composite for White Light Emission
2016Co-Authors: P. Ilaiyaraja, Pavana S. V. Mocherla, T. K. Srinivasan, Chandran SudakarAbstract:Cu-deficient graded-zinc Cu–In–Zn–S (CIZS) quantum dots (QDs) were synthesized by a two-step solvothermal method. These CIZS QDs exhibited size and composition tunable photoluminescence characteristics with emission color tunable from greenish-yellow to orange to red with a relatively high quantum yield between 45 and 60%. Novel white-light-emitting (WLE) hybrid composite is fabricated by integrating the blue-emissive 1,4-bis-2-(5-phenyl oxazolyl)-benzene (POPOP) organic fluorophore and quaternary CIZS inorganic QDs. Integrating CIZS QDs with POPOP fluorophore resulted in series of tunable emission colors with CIE coordinates lying in a straight line between the coordinates of the end member. WLE was shown for hybrid mixture comprising 0.5 nM of POPOP and 3 mg/mL of CIZS QDs with color coordinates (0.3312, 0.3324). Thin films of this hybrid mixture in PMMA matrix coated on UV-LED or on glass substrates with UV backlit light also showed broadband WLE with ideal CIE color coordinates of (0.34, 0.33), high color-rendering index value of 92, and correlated color temperature value of 5143 K. The hybrid composite exhibit Forster resonance energy transfer cascading from POPOP to CIZS which results in emission covering the entire visible spectral range. POPOP and CIZS QDs hybrid composite is a versatile material for WLED applications