Jahn-Teller effects in the photoluminescence excitation spectrum of vanadium-doped GaAs

1993 ◽  
Vol 48 (7) ◽  
pp. 4433-4436 ◽  
Author(s):  
Y. J. Kao ◽  
N. M. Haegel
Keyword(s):  
Excitation Spectrum ◽  
Photoluminescence Excitation ◽  
Photoluminescence Excitation Spectrum ◽  
Jahn Teller

scholarly journals Исследование свойств двумерных пленок МоS-=SUB=-2-=/SUB=- и WS-=SUB=-2-=/SUB=-, синтезированных химическим газофазным методом

2020 ◽  
Vol 54 (4) ◽  
pp. 376
Author(s):  
С.А. Смагулова ◽  
П.В. Винокуров ◽  
А.А. Семенова ◽  
Е.И. Попова ◽  
Ф.Д. Васильева ◽  
...  
Keyword(s):  
Excitation Spectrum ◽  
Single Layer ◽  
Chemical Vapor ◽  
Visible Spectral Range ◽  
Maximum Intensity ◽  
Photoluminescence Intensity ◽  
Photoluminescence Excitation ◽  
Excitation Light ◽  
Photoluminescence Excitation Spectrum ◽  
Atomic Vibrations

Abstract Molybdenum- and tungsten-disulfide films are synthesized by chemical-vapor deposition. The set of optimal synthesis parameters (temperature, time, and amount and ratio of precursors) is established at which MoS_2 domains with maximum lateral sizes of up to 250 μm on sapphire and MoS_2 and WS_2 domains up to 80 μm in size on SiO_2 can be grown. Domain intergrowth leads to the formation of homogeneous single-layer MoS_2 films. The Raman spectra of the synthesized films contain two characteristic peaks corresponding to the atomic vibrations in MoS_2 and WS_2. Photoluminescence of the single-layer and bilayer MoS_2 films with a maximum intensity of 670 ± 2 nm and of the single-layer WS_2 films with a maximum intensity of 630 ± 2 nm is detected. The photoluminescence spectral maps (the dependences of the photoluminescence intensity on the luminescence and excitation-light wavelengths) are measured. According to the measured data, the photoluminescence excitation spectrum of MoS_2 has a maximum at 350 ± 5 nm and the photoluminescence excitation spectrum of WS_2 has a maximum at 330 ± 5 nm. The I – V characteristics of the synthesized films are photosensitive in the visible spectral range.

scholarly journals Thermal Relaxation Spectra for Evaluating Luminescence Quantum Efficiency of CASN:Eu2+ Measured by Balanced-Detection Sagnac-Interferometer Photothermal Deflection Spectroscopy

2020 ◽  
Vol 10 (3) ◽  
pp. 1008
Author(s):  
Hiromichi Chima ◽  
Naoyuki Shiokawa ◽  
Keisuke Seto ◽  
Kohsei Takahashi ◽  
Naoto Hirosaki ◽  
...  
Keyword(s):  
Excitation Spectrum ◽  
Quantum Efficiency ◽  
Thermal Relaxation ◽  
Photoluminescence Excitation ◽  
Sagnac Interferometer ◽  
Excitation Spectra ◽  
Radiative Relaxation ◽  
Relaxation Spectra ◽  
Balanced Detection ◽  
Photothermal Deflection

Highly sensitive broadband photothermal spectroscopy with a white-light lamp as the excitation source was developed by combining a Sagnac interferometer and balanced detection with a photothermal deflection method. A probe beam was split by a birefringent crystal CaCO3 into signal and reference beams with a balanced intensity. This balanced detection enabled the measurement of photoexcited thermal relaxation spectra of materials in the air over the whole visible range in the weak excitation limit 50 µW/cm2. The photothermal excitation spectrum of Eu2+-doped CaAlSiN3 phosphors (CASN:Eu2+) with a high luminescent quantum efficiency was measured to be distinctly different from the photoluminescence excitation spectrum which reflects the absorption spectrum, revealing the thermal relaxation mechanism of the phosphor. Assuming a typical non-radiative relaxation from the higher excited states to the lowest excited state and successively to the ground state, it is demonstrated that the photoluminescence efficiency of the phosphors is readily evaluated simply by comparing the photothermal and photoluminescence excitation spectra.

Excitation spectrum ofFe2+in a tetrahedral potential: Dynamic Jahn-Teller effect

1995 ◽  
Vol 51 (8) ◽  
pp. 4849-4857 ◽  
Author(s):  
David Colignon ◽  
E. Kartheuser ◽  
Sergio Rodriguez ◽  
Murielle Villeret
Keyword(s):  
Excitation Spectrum ◽  
Teller Effect ◽  
Jahn Teller ◽  
Jahn Teller Effect

Magnon Excitation Spectrum in Ferromagnetic Quasicubic Manganites

2010 ◽  
Vol 46 (6) ◽  
pp. 1295-1298 ◽  
Author(s):  
P. Schlottmann
Keyword(s):  
Excitation Spectrum ◽  
Spin Wave ◽  
Heisenberg Model ◽  
Double Exchange ◽  
Zone Boundary ◽  
Wave Approximation ◽  
Hund’S Rule ◽  
Jahn Teller ◽  
Hund's Rule ◽  
Magnon Excitation

The magnon excitation spectrum of ferromagnetic quasicubic manganites is studied by using the linearized spin-wave approximation for the double-exchange and the superexchange interactions. Two situations are distinguished: 1) a rigid coupling of the t2gand egspins via a large Hund's rule coupling and 2) a softened coupling between these spins (e.g., due to coupling of the egelectrons to Jahn-Teller modes). Case 2) leads to a softening of the magnon dispersion (compared to the Heisenberg model) close to the zone boundary.

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