Photolysis of Thiolane Vapor

1971 ◽  
Vol 49 (8) ◽  
pp. 1316-1320 ◽  
Author(s):  
Silvia Braslavsky ◽  
Julian Heicklen
Keyword(s):  
Quantum Yield ◽  
Excited States ◽  
Room Temperature ◽  
Major Product ◽  
Unstable Product

The photolysis of thiolane vapor [Formula: see text] was studied at room temperature with 2139 Å radiation. The major product was C2H4, whose quantum yield decreased as the pressure was increased. Next in importance were 1-C4H8, C3H6, and C2H6. Also produced were CH4, c-C3H6, 1,3-C4H6, CH2CHSH, [Formula: see text], 1-C4H9SH, H2, C3H8, n-C4H10, c-C4H8, polymer, and an unstable product tentatively identified as 1-butene-1-thiol. All products were initial products of the reaction. Experiments with added C3H6 showed the absence of sulfur atoms. The results are interpreted in terms of two excited states and an intermediate which might be the diradical •CH2CH2CH2CH2S•.

Room temperature synthesis of Sn2+ doped highly luminescent CsPbBr3 quantum dots for high CRI white light-emitting diodes

Nanoscale ◽  
2021 ◽  
Author(s):  
Dongdong Yan ◽  
Qionghua Mo ◽  
Shuangyi Zhao ◽  
Wensi Cai ◽  
Zhigang Zang
Keyword(s):  
Quantum Dots ◽  
Quantum Yield ◽  
White Light ◽  
Room Temperature ◽  
Temperature Synthesis ◽  
Light Emitting ◽  
Photoluminescence Quantum Yield ◽  
Hot Injection ◽  
White Light Emitting Diodes ◽  
Cspbbr3 Quantum Dots

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...

scholarly journals Modulation of charge transfer by N-alkylation to control photoluminescence energy and quantum yield

2020 ◽  
Vol 11 (27) ◽  
pp. 6990-6995 ◽  
Author(s):  
Andrew T. Turley ◽  
Andrew Danos ◽  
Antonio Prlj ◽  
Andrew P. Monkman ◽  
Basile F. E. Curchod ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Quantum Yield ◽  
Excited States

A versatile N-alkylation strategy controls the presence of charge-transfer excited states and the emission colour of N-heterocyclic chromophores.

scholarly journals Enhanced Room‐Temperature Photoluminescence Quantum Yield in Morphology Controlled J‐Aggregates

2021 ◽  
pp. 1903080
Author(s):  
Surendra B. Anantharaman ◽  
Joachim Kohlbrecher ◽  
Gabriele Rainò ◽  
Sergii Yakunin ◽  
Thilo Stöferle ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Room Temperature ◽  
Room Temperature Photoluminescence ◽  
Photoluminescence Quantum Yield ◽  
J Aggregates

scholarly journals Excited states and quantum confinement in room temperature few nanometre scale silicon single electron transistors

2017 ◽  
Vol 28 (12) ◽  
pp. 125208 ◽  
Author(s):  
Zahid A K Durrani ◽  
Mervyn E Jones ◽  
Chen Wang ◽  
Dixi Liu ◽  
Jonathan Griffiths
Keyword(s):  
Excited States ◽  
Quantum Confinement ◽  
Room Temperature ◽  
Single Electron ◽  
Single Electron Transistors ◽  
Electron Transistors

Comparison of the Optical Properties of Er3+ Doped Gallium Nitride Prepared by Metalorganic Molecular Beam Epitaxy (MOMBE) and Solid Source Molecular Beam Epitaxy (SSMBE)

1999 ◽  
Vol 595 ◽  
Author(s):  
U. Hömmerich ◽  
J. T. Seo ◽  
J. D. MacKenzie ◽  
C. R. Abernathy ◽  
R. Birkhahn ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Excited States ◽  
Room Temperature ◽  
Molecular Beam ◽  
Average Lifetime ◽  
Green Luminescence ◽  
Si Substrates ◽  
Lifetime Analysis ◽  
Metalorganic Molecular Beam Epitaxy ◽  
Er Doped

AbstractWe report on the luminescence properties of Er doped GaN grown prepared by metalorganic molecular beam epitaxy (MOMBE) and solid-source molecular beam epitaxy (SSMBE) on Si substrates. Both types of samples emitted characteristic 1.54 µm PL resulting from the intra-4f Er3+ transition 4I13/2→4I15/2. Under below-gap excitation the samples exhibited very similar 1.54 µm PL intensities. On the contrary, under above-gap excitation GaN: Er (SSMBE) showed ∼80 times more intense 1.54 µm PL than GaN: Er (MOMBE). In addition, GaN: Er (SSMBE) also emitted intense green luminescence at 537 nm and 558 nm, which was not observed from GaN: Er (MOMBE). The average lifetime of the green PL was determined to be 10.8 µs at 15 K and 5.5 µs at room temperature. A preliminary lifetime analysis suggests that the decrease in lifetime is mainly due to the strong thermalization between the 2H11/2 and 4S3/2 excited states. Nonradiative decay processes are expected to only weakly affect the green luminescence.

The photochemical and thermal decompositions of hydrogen sulphide

1953 ◽  
Vol 216 (1126) ◽  
pp. 344-361 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Quantum Yield ◽  
Hydrogen Sulphide ◽  
Low Temperatures ◽  
Room Temperature ◽  
Large Fraction ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Photochemical Decomposition ◽  
Bimolecular Mechanism

The photochemical decomposition of hydrogen sulphide has been investigated at pressures between 8 and 550 mm of mercury and at temperatures between 27 and 650° C, using the narrow cadmium line ( λ 2288) and the broad mercury band (about λ 2550). At room temperature the quantum yield increases with pressure from 1.09 at 30 mm to 1.26 at 200 mm. Above 200 mm pressure there was no further increase in the quantum yield. Temperature had little effect on the quantum yield at λ 2550, but there was a marked increase in the rate of hydrogen production between 500 and 650° C with 2288 Å radiation. This may have been caused by the decomposition of excited hydrosulphide radicals. The results are consistent with a mechanism involving hydrogen atoms and hydrosulphide radicals. The mercury-photosensitized reaction is less efficient than the photochemical decomposition, the quantum yield being only about 0.45. The efficiency increased with temperature and approached unity at high temperatures and pressures. This agrees with the suggestion that a large fraction of the quenching collisions lead to the formation of Hg ( 3 P 0 ) atoms. The thermal decomposition is heterogeneous at low temperatures and becomes homogeneous and of the second order at 650° C. The experimental evidence suggests the bimolecular mechanism 2H 2 S → 2H 2 + S 2 . The activation energies are 25 kcal/mole (heterogeneous) and 50 kcal/mole (homogeneous).

Synthesis and luminescence properties of colloidal lanthanide doped YVO4

2001 ◽  
Vol 667 ◽  
Author(s):  
Arnaud Huignard ◽  
Thierry Gacoin ◽  
Frédéric Chaput ◽  
Jean-Pierre Boilot ◽  
Patrick Aschehoug ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Room Temperature ◽  
Sol Gel ◽  
Precursor Solution ◽  
Silica Matrix ◽  
Luminescence Quantum Yield ◽  
Colloidal Solutions ◽  
Silicon Alkoxide ◽  
Crystalline Defects ◽  
Hydroxylated Surface

ABSTRACTAqueous colloidal solutions of well dispersed YVO4:Ln (Ln = Eu, Nd) nanoparticles are synthesized through precipitation reactions at room temperature. In the case of YVO4:Eu, a luminescence quantum yield of 15% is found, which is not as high as in the bulk due to the existence of residual crystalline defects and nonradiative relaxations from the hydroxylated surface. Appropriate hydrothermal annealing and deuteration of the surface allow to rise the yield up to 38%. Incorporation of the nanocrystals into a transparent silica matrix is achieved through preliminary coating of the particles with a functionnalized silicon alkoxide and further dispersion into a sol-gel precursor solution. Such sol-gel materials doped with YVO4:Nd nanocrystals are transparent and exhibit the typical emission at 1.06 μm of the Nd3+ ion.

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