Temperature Dependent Radiative Lifetime of J-Aggregates

1996 ◽  
Vol 100 (21) ◽  
pp. 8640-8644 ◽  
Author(s):  
Valey F. Kamalov ◽  
Irina A. Struganova ◽  
Keitaro Yoshihara
Keyword(s):  
Radiative Lifetime ◽  
Temperature Dependent ◽  
J Aggregates

Dimensionality and temperature dependence of the radiative lifetime of J-aggregates with Davydov splitting of the exciton band

2000 ◽  
Vol 316 (1-2) ◽  
pp. 37-44 ◽  
Author(s):  
I.G. Scheblykin ◽  
M.M. Bataiev ◽  
M. Van der Auweraer ◽  
A.G. Vitukhnovsky
Keyword(s):  
Temperature Dependence ◽  
Radiative Lifetime ◽  
Exciton Band ◽  
J Aggregates

Temperature dependent exciton radiative lifetime in ZnO nanorods

2007 ◽  
Vol 4 (4) ◽  
pp. 404
Author(s):  
X.H. Zhang ◽  
S.J. Chua ◽  
A.M. Yong ◽  
H.Y. Yang ◽  
S.P. Lau ◽  
...  
Keyword(s):  
Radiative Lifetime ◽  
Zno Nanorods ◽  
Temperature Dependent

Temperature-Dependent Exciton Properties of Two Cylindrical J-Aggregates

2014 ◽  
Vol 118 (42) ◽  
pp. 24325-24334 ◽  
Author(s):  
Katie A. Clark ◽  
Emma L. Krueger ◽  
David A. Vanden Bout
Keyword(s):  
Temperature Dependent ◽  
J Aggregates

scholarly journals Quantum Beats in Transient Spectroscopy of J-Aggregates

1996 ◽  
Vol 16 (3) ◽  
pp. 179-196
Author(s):  
H. Glaeske ◽  
K.-H. Feller ◽  
E. Gaišaukas ◽  
L. Knöll
Keyword(s):  
Transient Absorption ◽  
Temporal Evolution ◽  
Quantum Beat ◽  
Quantum Beats ◽  
Level System ◽  
Temperature Dependent ◽  
Phase Relaxation ◽  
Experimental Conditions ◽  
J Aggregates ◽  
Transient Spectroscopy

Quantum beats in transient absorption of PIC-J-aggregates, modelled by a modified 3-level-system are calculated. Experimental conditions for the possibility of their observation are investigated. The influence of the temperature dependent phase relaxation on the temporal evolution of quantum beat signals is considered.

scholarly journals Bridging the Gap between H- and J-Aggregates: Classification and Supramolecular Tunability for Excitonic Band Structures in 2-Dimensional Molecular Aggregates

2021 ◽  
Author(s):  
Arundhati Deshmukh ◽  
Niklas Geue ◽  
Nadine Bardbury ◽  
Timothy Atallah ◽  
Chern Chuang ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Quantum Yields ◽  
Molecular Aggregates ◽  
Temperature Dependent ◽  
Excitonic Band ◽  
Spectral Shifts ◽  
Aggregate Properties ◽  
Higher Dimensional ◽  
J Aggregates ◽  
Shortwave Infrared

Molecular aggregates with long-range excitonic couplings have drastically different photophysical properties compared to their monomer counterparts. From Kasha’s model for 1-dimensional systems, positive or negative excitonic couplings lead to blue or red shifted optical spectra with respect to the monomers, labelled H-and J-aggregates respectively. The overall excitonic couplings in higher dimensional systems are much more complicated and cannot be simply classified from their spectral shifts alone. Here, we provide a unified classification for extended 2D aggregates using temperature dependent peak shifts, thermal broadening and quantum yields. We discuss the examples of six 2D aggregates with J-like absorption spectra but quite drastic changes quantum yields and superradiance. We find the origin of the differences is, in fact, a different excitonic band structure where the bright state is lower energy than the monomer but still away from the band edge. We call this an ‘I-aggregate’. Our results provide a description of the complex excitonic behaviors that cannot be explained solely on Kasha’s model. Further, such properties can be tuned with the packing geometries within the aggregates providing supramolecular pathways for controlling them. This will allow for precise optimizations of aggregate properties in their applications across the areas of optoelectronics, photonics, excitonic energy transfer, and shortwave infrared technologies.

scholarly journals Bridging the Gap between H- and J-Aggregates: Classification and Supramolecular Tunability for Excitonic Band Structures in 2-Dimensional Molecular Aggregates

2021 ◽  
Author(s):  
Arundhati Deshmukh ◽  
Niklas Geue ◽  
Nadine Bradbury ◽  
Timothy Atallah ◽  
Chern Chuang ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Quantum Yields ◽  
Molecular Aggregates ◽  
Temperature Dependent ◽  
Excitonic Band ◽  
Spectral Shifts ◽  
Aggregate Properties ◽  
Higher Dimensional ◽  
J Aggregates ◽  
Shortwave Infrared

Molecular aggregates with long-range excitonic couplings have drastically different photophysical properties compared to their monomer counterparts. From Kasha’s model for 1-dimensional systems, positive or negative excitonic couplings lead to blue or red shifted optical spectra with respect to the monomers, labelled H-and J-aggregates respectively. The overall excitonic couplings in higher dimensional systems are much more complicated and cannot be simply classified from their spectral shifts alone. Here, we provide a unified classification for extended 2D aggregates using temperature dependent peak shifts, thermal broadening and quantum yields. We discuss the examples of six 2D aggregates with J-like absorption spectra but quite drastic changes quantum yields and superradiance. We find the origin of the differences is, in fact, a different excitonic band structure where the bright state is lower energy than the monomer but still away from the band edge. We call this an ‘I-aggregate’. Our results provide a description of the complex excitonic behaviors that cannot be explained solely on Kasha’s model. Further, such properties can be tuned with the packing geometries within the aggregates providing supramolecular pathways for controlling them. This will allow for precise optimizations of aggregate properties in their applications across the areas of optoelectronics, photonics, excitonic energy transfer, and shortwave infrared technologies.

Temperature-Dependent Exciton Dynamics in J-Aggregates—When Disorder Plays a Role

2009 ◽  
Vol 113 (48) ◽  
pp. 15836-15842 ◽  
Author(s):  
Theo E. Kaiser ◽  
Ivan G. Scheblykin ◽  
Daniel Thomsson ◽  
Frank Würthner
Keyword(s):  
Temperature Dependent ◽  
Exciton Dynamics ◽  
J Aggregates

DISORDER-INDUCED RELAXATION OF FRENKEL EXCITONS IN MOLECULAR AGGREGATES

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3761-3764 ◽  
Author(s):  
M. BEDNARZ ◽  
J. P. LEMAISTRE
Keyword(s):  
Phonon Scattering ◽  
Radiative Lifetime ◽  
Relaxation Mechanism ◽  
One Dimensional ◽  
Excitonic Band ◽  
Fast Relaxation ◽  
J Aggregates ◽  
Chain Lengths ◽  
Allowed State ◽  
Pauli Master Equation

A model, based on the intraband scattering of excitons in one-dimensional J-aggregates is proposed to describe the lengthening of the experimentally observed radiative lifetime with temperature. According to this mechanism, the exciton-phonon scattering transfers the oscillator strength fromt he lowest k≅0 optically allowed state to the other states within the excitonic band. A Pauli master equation, in which the hopping rates are calculated, is used to describe the thermalization of the excitonic band. Assuming a fast relaxation mechanism, the temperature dependence of the exciton radiative lifetime is simulated for various chain lengths.

scholarly journals Temperature-Dependent and Threshold Behavior of Sm3+ Ions on Fluorescence Properties of Lithium Niobate Single Crystals

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2058 ◽  
Author(s):  
Mingming Yang ◽  
Siwei Long ◽  
Xin Yang ◽  
Shaopeng Lin ◽  
Yunzhong Zhu ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Single Crystals ◽  
Radiative Lifetime ◽  
Active Material ◽  
Branching Ratio ◽  
Emission Spectra ◽  
Fluorescence Properties ◽  
Threshold Behavior ◽  
Photoluminescence Spectra ◽  
Temperature Dependent

Temperature-dependent and threshold behavior of Sm3+ ions on fluorescence properties of lithium niobate (LiNbO3, LN) single crystals were systematically investigated. The test materials, congruent LiNbO3 single crystals (Sm:LN), with various concentrations of doped Sm3+ ions from 0.2 to 2.0 mol.%, were grown using the Czochralski technique. Absorption spectra were obtained at room temperature, and photoluminescence spectra were measured at various temperatures in the range from 73 K to 423 K. Judd–Ofelt theory was applied to calculate the intensity parameters Ωt (t = 2, 4, 6) for 1.0 mol.% Sm3+-doped LiNbO3, as well as the radiative transition rate, Ar, branching ratio, β, and radiative lifetime, τr, of the fluorescent 4G5/2 level. Under 409 nm laser excitation, the photoluminescence spectra of the visible fluorescence of Sm3+ mainly contains 568, 610, and 651 nm emission spectra, corresponding to the energy level transitions of 4G5/2→6H5/2, 4G5/2→6H7/2, and 4G5/2→6H9/2, respectively. The concentration of Sm3+ ions has great impact on the fluorescence intensity. The luminescence intensity of Sm (1.0 mol.%):LN is about ten times as against Sm (0.2 mol.%):LN at 610 nm. The intensity of the fluorescence spectra were found to be highly depend on temperature, as well as the concentration of Sm3+ ions in LiNbO3 single crystals, as predicted; however, the lifetime changed little with the temperature, indicating that the temperature has little effect on it, in Sm:LN single crystals. Sm:LN single crystals, with orange-red emission spectra, can be used as the active material in new light sources, fluorescent display devices, UV-sensors, and visible lasers.

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