Nearly degenerate time-resolved faraday rotation in quantum wells: The role of exciton-exciton interactions

2006 ◽  
Author(s):  
Yumin Shen ◽  
Alexander Goebel ◽  
G. Khitrova ◽  
H.M. Gibbs ◽  
Hailin Wang
Keyword(s):  
Quantum Wells ◽  
Faraday Rotation ◽  
Time Resolved ◽  
Exciton Interactions

Time-Resolved Nonlinear Faraday Rotation in Semimagnetic Quantum Wells

1997 ◽  
Vol 204 (1) ◽  
pp. 49-51
Author(s):  
R. Pankoke ◽  
P. Leisching ◽  
C. Buss ◽  
R. Frey ◽  
J. Cibert ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Faraday Rotation ◽  
Time Resolved ◽  
Nonlinear Faraday Rotation

scholarly journals Time-resolved Faraday rotation measurements of spin relaxation in InGaAs∕GaAs quantum dots: Role of excess energy

2007 ◽  
Vol 90 (15) ◽  
pp. 153118 ◽  
Author(s):  
J. L. Robb ◽  
Y. Chen ◽  
A. Timmons ◽  
K. C. Hall ◽  
O. B. Shchekin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Spin Relaxation ◽  
Faraday Rotation ◽  
Excess Energy ◽  
Time Resolved

scholarly journals Role of dislocations in nitride laser diodes with different indium content

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agata Bojarska-Cieślińska ◽  
Łucja Marona ◽  
Julita Smalc-Koziorowska ◽  
Szymon Grzanka ◽  
Jan Weyher ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Defect Density ◽  
Laser Diodes ◽  
Diffusion Path ◽  
Vapour Phase ◽  
Indium Content ◽  
Nonradiative Recombination ◽  
Light Emitters ◽  
Vapour Phase Epitaxy

AbstractIn this work we investigate the role of threading dislocations in nitride light emitters with different indium composition. We compare the properties of laser diodes grown on the low defect density GaN substrate with their counterparts grown on sapphire substrate in the same epitaxial process. All structures were produced by metalorganic vapour phase epitaxy and emit light in the range 383–477 nm. We observe that intensity of electroluminescence is strong in the whole spectral region for devices grown on GaN, but decreases rapidly for the devices on sapphire and emitting at wavelength shorter than 420 nm. We interpret this behaviour in terms of increasing importance of dislocation related nonradiative recombination for low indium content structures. Our studies show that edge dislocations are the main source of nonradiative recombination. We observe that long wavelength emitting structures are characterized by higher average light intensity in cathodoluminescence and better thermal stability. These findings indicate that diffusion path of carriers in these samples is shorter, limiting the amount of carriers reaching nonradiative recombination centers. According to TEM images only mixed dislocations open into the V-pits, usually above the multi quantum wells thus not influencing directly the emission.

Role of Metal Vacancies in the Mechanism of Thermal Degradation of InGaN Quantum Wells

2021 ◽  
Vol 13 (6) ◽  
pp. 7476-7484
Author(s):  
Julita Smalc-Koziorowska ◽  
Ewa Grzanka ◽  
Artur Lachowski ◽  
Roman Hrytsak ◽  
Mikolaj Grabowski ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Quantum Wells ◽  
Metal Vacancies ◽  
Ingan Quantum Wells

scholarly journals The role of spin in the degradation of organic photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ivan Ramirez ◽  
Alberto Privitera ◽  
Safakath Karuthedath ◽  
Anna Jungbluth ◽  
Johannes Benduhn ◽  
...  
Keyword(s):  
Transient Absorption ◽  
Bulk Heterojunction ◽  
Critical Factor ◽  
Model Systems ◽  
Transient Absorption Spectroscopy ◽  
Triplet States ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
A Charge

AbstractStability is now a critical factor in the commercialization of organic photovoltaic (OPV) devices. Both extrinsic stability to oxygen and water and intrinsic stability to light and heat in inert conditions must be achieved. Triplet states are known to be problematic in both cases, leading to singlet oxygen production or fullerene dimerization. The latter is thought to proceed from unquenched singlet excitons that have undergone intersystem crossing (ISC). Instead, we show that in bulk heterojunction (BHJ) solar cells the photo-degradation of C60 via photo-oligomerization occurs primarily via back-hole transfer (BHT) from a charge-transfer state to a C60 excited triplet state. We demonstrate this to be the principal pathway from a combination of steady-state optoelectronic measurements, time-resolved electron paramagnetic resonance, and temperature-dependent transient absorption spectroscopy on model systems. BHT is a much more serious concern than ISC because it cannot be mitigated by improved exciton quenching, obtained for example by a finer BHJ morphology. As BHT is not specific to fullerenes, our results suggest that the role of electron and hole back transfer in the degradation of BHJs should also be carefully considered when designing stable OPV devices.

scholarly journals Time-resolved observation of ballistic acceleration of electrons in GaAs quantum wells

1992 ◽  
Vol 7 (3B) ◽  
pp. B133-B136 ◽  
Author(s):  
W Sha ◽  
T B Norris ◽  
W J Schaff ◽  
K E Meyer
Keyword(s):  
Quantum Wells ◽  
Time Resolved

Anomalous Mn Spin Resonance Detected by Time-Resolved Kerr Effect in CdMnTe Quantum Wells

2002 ◽  
Vol 190 (3) ◽  
pp. 715-718 ◽  
Author(s):  
F. Teppe ◽  
C. Camilleri ◽  
D. Scalbert ◽  
Y.G. Semenov ◽  
M. Nawrocki ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Kerr Effect ◽  
Time Resolved ◽  
Spin Resonance
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