scholarly journals Роль модельных представлений в описании кинетики люминесценции гибридных нитевидных нанокристаллов

2020 ◽  
Vol 128 (1) ◽  
pp. 122
Author(s):  
А.С. Кулагина ◽  
А.И. Хребтов ◽  
Р.Р. Резник ◽  
Е.В. Убыйвовк ◽  
А.П. Литвин ◽  
...  
Keyword(s):  
Room Temperature ◽  
Theoretical Models ◽  
Decay Kinetics ◽  
Semiconductor Structures ◽  
Long Duration ◽  
State Radiation ◽  
Radiation Lifetime ◽  
Kinetics Of ◽  
Luminescence Decay Kinetics

On the example of InP/InAsP/InP nanowires, the role of theoretical models in the photodynamics study of hybrid semiconductor structures is considered. The photodynamics of luminescence of an array of InP/InAsP/InP nanowires formed by molecular beam epitaxy on a Si (III) substrate was studied. Based on a comparison of several kinetic models, including the use of poly-exponential and stretched-exponential functions, the analysis of experimental data is carried out. Experiments were performed by excitation with laser radiation of 633 nm at room temperature. It has been shown that the luminescence decay kinetics of the InAsP nanoinsert is best described in terms of the contact quenching model. The total decay time of the excited state (radiation lifetime) of the InAsP insert was estimated at τ ~ 40 ns. The reasons for the unusually long duration of transfer of excitation from InP have been suggested.

Growing Features and Luminescence of Bi3+ Ions in Gd3Ga5O12 Epitaxial Films

2013 ◽  
Vol 200 ◽  
pp. 215-219 ◽  
Author(s):  
Andriy P. Luchechko ◽  
Igor I. Syvorotka ◽  
Yaroslav Zakharko ◽  
I.M. Syvorotka
Keyword(s):  
Room Temperature ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Growth Conditions ◽  
Excitation Wavelength ◽  
Decay Kinetics ◽  
Exponential Behavior ◽  
Crystalline Films ◽  
Kinetics Of ◽  
Luminescence Decay Kinetics

Abstract. Excitation and emission spectra under UV and X-ray excitations, as well as the luminescence decay kinetics of Gd3Ga5O12: Bi single crystalline films were studied. The emission spectra observed in the spectral region 350-700 nm at room temperature consist two elementary bands peaked at 446 and 521 nm. The influence of growth conditions on the luminescent properties of Gd3Ga5O12: Bi3+ garnet have been revealed. The integral and relative intensities of the luminescence bands depend on the excitation wavelength. The Bi3+ decay curves of all investigated films show non-single exponential behavior at room temperature.

Photoluminescence of Eu3+ Ions in Lu3(Ga,In)5O12:Eu3+ Films Grown by LPE Method

2015 ◽  
Vol 230 ◽  
pp. 166-171
Author(s):  
Andriy Luchechko ◽  
I.I. Syvorotka ◽  
Yaroslav Zakharko ◽  
Igor M. Syvorotka
Keyword(s):  
Room Temperature ◽  
Emission Spectra ◽  
Epitaxial Films ◽  
Decay Kinetics ◽  
Exponential Behavior ◽  
Efficient Energy Transfer ◽  
Kinetics Of ◽  
Uv Excitation ◽  
The Eu ◽  
Luminescence Decay Kinetics

High quality thin epitaxial films of Lu3(Ga,In)5O12:Eu3+ were grown by liquid phase epitaxy (LPE) method from Bi2O3-based flux. Excitation and emission spectra as well as luminescence decay kinetics of Lu3(Ga,In)5O12:Eu3+ epitaxial films were studied under UV excitation. The photoluminescence spectra of Eu3+ ions in Lu3(Ga,In)5O12:Eu3+ are characteristic to the f→f transition in the Eu3+ ions that occupied dodecahedral sites in the garnet structure. The efficient energy transfer between Bi3+→Eu3+ is observed at the excitation of Lu3(Ga,In)5O12:Eu3+ films in Bi3+ excitation band with maximum at 288 nm. The Eu3+ decay curves of all investigated films show non-single exponential behavior at room temperature.

Di-imide: Some Physical and Chemical Properties, and the Kinetics and Stoichiometry of the Gas-phase Decomposition

1973 ◽  
Vol 51 (21) ◽  
pp. 3605-3619 ◽  
Author(s):  
C. Willis ◽  
R. A. Back
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Chemical Properties ◽  
Phase Decomposition ◽  
Important Intermediate ◽  
Long Lifetime ◽  
Physical And Chemical ◽  
Text Formation ◽  
Kinetics Of

Preparation of di-imide by passing hydrazine vapor through a microwave discharge yields mixtures with NH3 containing typically about 15% N2H2, estimated from the gases evolved on decomposition. The behavior of the mixture (which melts at −65 °C) on warming from −196 to −30 °C suggests a strong interaction between the components. Measurements of magnetic susceptibility and e.p.r. experiments showed that N2H2 is not strongly paramagnetic, which with other observations points to a singlet rather than a triplet ground-state.Di-imide can be vaporized efficiently, together with NH3, by rapid warming, and the vapor is surprisingly long-lived, with a typical half-life of several minutes at room temperature. The near-u.v. (3200–4400 Å) absorption spectrum of the vapor was photographed; it shows well-defined but diffuse bands, with εmax = 6(± 3) at 3450 Å.Di-imide decomposes at room temperature in two ways:[Formula: see text][Formula: see text]Formation of NH3 was not observed but cannot be ruled out. The decomposition of the vapor is complicated by a sizeable and variable decomposition that occurs rapidly during the vaporization. The stoichiometry of this and the vapor-phase decomposition depends on total pressure and di-imide concentration. The kinetics of the decomposition of the vapor were studied from 22 to 200 °C by following the disappearance of N2H2 by absorption of light at 3450 Å, or the formation of N2H4 by absorption at 2400 Å, and by mass spectrometry. The kinetics are complex and can be either first- or second-order, or mixed, depending on surface conditions. The effect of olefin additives on the decomposition was studied, and is also complex.Mechanisms for the decomposition are discussed, including the possible role of trans-cis isomerization. The relatively long lifetime found for di-imide in the gas phase suggests that it may be an important intermediate in many reactions of hydronitrogen systems.

Revisiting the Luminescence Decay Kinetics of Energy Transfer Upconversion

2020 ◽  
Vol 11 (9) ◽  
pp. 3672-3680
Author(s):  
Jintao Kong ◽  
Xiaoying Shang ◽  
Wei Zheng ◽  
Xueyuan Chen ◽  
Datao Tu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Luminescence Decay ◽  
Decay Kinetics ◽  
Energy Transfer Upconversion ◽  
Kinetics Of ◽  
Luminescence Decay Kinetics

scholarly journals Role of Electronic Excited State in Kinetics of the CH2OO + SO2 ! HCHO + SO3 Reaction

2021 ◽  
Author(s):  
Qingfei Song ◽  
Qiuyu Zhang ◽  
Qingyong Meng
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Energy Surface ◽  
Regression Method ◽  
Vibrationally Excited ◽  
Compute Data ◽  
Ring Polymer ◽  
Experimental Values ◽  
Kinetics Of

In this work, kinetics of the CH2OO + SO2 ! HCHO + SO3 reaction was studied by ring-polymer molecular dynamics (RPMD). To perform RPMD calculations, multi-reference configuration interaction (MRCI) was first carried out to compute data for constructing potential energy surface (PES) through a kernel regression method. On the basis of the present MRCI calculations, the statics multi-state mechanism involving the lowest-lying singlet excited state (denoted by S 1) was proposed, which is di?erent from the previously proposed mechanism with the lowest-lying triplet state (denoted by T1). Moreover, the present RPMD calculations predicted the rate coe?cient of 3:95?10􀀀11cm3 molecule􀀀1s􀀀1 at the room temperature (namely 298 K), agreeing with the previously reported experimental values. Finally, based on the present calculations, a probable dynamics mechanism was discussed, where the produced HCHO molecule was proposed to be in a vibrationally excited state. This needs further experimental and theoretical observation in the future.<br>

scholarly journals Role of Electronic Excited State in Kinetics of the CH2OO + SO2 ! HCHO + SO3 Reaction

2021 ◽  
Author(s):  
Qingfei Song ◽  
Qiuyu Zhang ◽  
Qingyong Meng
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Energy Surface ◽  
Regression Method ◽  
Vibrationally Excited ◽  
Compute Data ◽  
Ring Polymer ◽  
Experimental Values ◽  
Kinetics Of

In this work, kinetics of the CH2OO + SO2 ! HCHO + SO3 reaction was studied by ring-polymer molecular dynamics (RPMD). To perform RPMD calculations, multi-reference configuration interaction (MRCI) was first carried out to compute data for constructing potential energy surface (PES) through a kernel regression method. On the basis of the present MRCI calculations, the statics multi-state mechanism involving the lowest-lying singlet excited state (denoted by S 1) was proposed, which is di?erent from the previously proposed mechanism with the lowest-lying triplet state (denoted by T1). Moreover, the present RPMD calculations predicted the rate coe?cient of 3:95?10􀀀11cm3 molecule􀀀1s􀀀1 at the room temperature (namely 298 K), agreeing with the previously reported experimental values. Finally, based on the present calculations, a probable dynamics mechanism was discussed, where the produced HCHO molecule was proposed to be in a vibrationally excited state. This needs further experimental and theoretical observation in the future.<br>

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