scholarly journals Photocharging dynamics in colloidal CdS quantum dots visualized by electron spin coherence

2018 ◽  
Vol 52 (4) ◽  
pp. 489
Author(s):  
D.R. Yakovlev ◽  
D.H. Feng ◽  
V.V. Pavlov ◽  
A.V. Rodina ◽  
E.V. Shornikova ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Spin Dynamics ◽  
Surface States ◽  
Laser Pulses ◽  
Spin Coherence ◽  
Core Electron ◽  
Time Resolved ◽  
Hole Trapping ◽  
Colloidal Cds

AbstractWe use a time-resolved technique with three laser pulses (pump, orientation and probe) to study the photocharging dynamics with picosecond resolution on a long timescale ranging from ps to ms in CdS colloidal quantum dots. The detection is based on measuring the coherent spin dynamics of electrons, allowing us to distinguish the type of carrier in the dot core (electron or hole). We find that although initially negative photocharging happens because of fast hole trapping on surface states, eventually it evolves to positive photocharging due to electron trapping and hole detrapping. The positive photocharging lasts up to hundreds of microseconds at room temperature.

Long-lived, room-temperature electron spin coherence in colloidal CdS quantum dots

2012 ◽  
Vol 100 (12) ◽  
pp. 122406 ◽  
Author(s):  
D. H. Feng ◽  
X. Li ◽  
T. Q. Jia ◽  
X. Q. Pan ◽  
Z. R. Sun ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Spin ◽  
Room Temperature ◽  
Cds Quantum Dots ◽  
Spin Coherence ◽  
Temperature Electron ◽  
Colloidal Cds

scholarly journals Room-Temperature Electron Spin Generation by Femtosecond Laser Pulses in Colloidal CdS Quantum Dots

Materials ◽  
2013 ◽  
Vol 6 (10) ◽  
pp. 4523-4531 ◽  
Author(s):  
Haifang Tong ◽  
Donghai Feng ◽  
Xiao Li ◽  
Li Deng ◽  
Yuxin Leng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Femtosecond Laser ◽  
Electron Spin ◽  
Room Temperature ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Cds Quantum Dots ◽  
Temperature Electron ◽  
Colloidal Cds

scholarly journals Photooxidation and Photobleaching of Single CdSe/ZnS Quantum Dots Probed by Room-Temperature Time-Resolved Spectroscopy

2001 ◽  
Vol 105 (35) ◽  
pp. 8281-8284 ◽  
Author(s):  
Wilfried G. J. H. M. van Sark ◽  
Patrick L. T. M. Frederix ◽  
Dave J. Van den Heuvel ◽  
Hans C. Gerritsen ◽  
Ageeth A. Bol ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Temperature Time

scholarly journals Спиновая динамика отрицательно заряженных экситонов в квантовых точках InP/(In,Ga)P в магнитном поле

2020 ◽  
Vol 62 (11) ◽  
pp. 1816
Author(s):  
С.В. Некрасов ◽  
Ю.Г. Кусраев ◽  
И.А. Акимов ◽  
L. Langer ◽  
M. Kotur ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Circular Polarization ◽  
Ground State ◽  
Heavy Hole ◽  
Spin Dynamics ◽  
Nuclear Spins ◽  
Time Resolved ◽  
Exciton Ground State ◽  
Charged Exciton

The dynamics of the photoluminescence negative circular polarization of the InP/(In,Ga)P quantum dots ensemble was studied. We find that in the time-resolved dependences of the polarization there are no oscillations in Voigt magnetic field. Also, with increasing field the polarization declines to zero. Such behavior is attributed to the peculiarities of the negatively charged exciton spin dynamics, particularly, to the fact that in the negatively charged exciton ground state the spin dynamics is governed by the heavy hole. We show that magnetic field depolarization of the photoluminescence occurs once the field of dynamically polarized nuclear spins acting on electron spins is surpassed.

Photocharging Dynamics in Colloidal CdS Quantum Dots Visualized by Electron Spin Coherence

2018 ◽  
Vol 52 (4) ◽  
pp. 548-550
Author(s):  
D. R. Yakovlev ◽  
D. H. Feng ◽  
V. V. Pavlov ◽  
A. V. Rodina ◽  
E. V. Shornikova ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Spin ◽  
Cds Quantum Dots ◽  
Spin Coherence ◽  
Colloidal Cds

Vapour Sensitivity of InP Surface Quantum Dots

2014 ◽  
Vol 605 ◽  
pp. 177-180 ◽  
Author(s):  
Roberta de Angelis ◽  
Mauro Casalboni ◽  
Liliana D’Amico ◽  
Fabio de Matteis ◽  
Fariba Hatami ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Near Infrared ◽  
Surface Recombination ◽  
Surface States ◽  
Infrared Emission ◽  
Polar Solvents ◽  
Solvent Type ◽  
Near Infrared Emission ◽  
Inp Surface

We studied the effect of solvent vapours on the photoluminescent emission of self-assembled InP surface quantum dots (SQDs). Their room temperature near infrared emission undergoes a fully reversible intensity enhancement when the dots were exposed to vapours of polar solvents since polar molecules are likely to be adsorbed onto intrinsic surface states and thus reducing non radiative surface recombination. The shape and position of the emission band does not change. The observed effect is dependent on solvent type and concentration with linear law over a limited concentration range.

ELECTRON SPIN COHERENCE IN SINGLY CHARGED QUANTUM DOTS

2009 ◽  
Vol 23 (12n13) ◽  
pp. 2813-2825
Author(s):  
D. R. YAKOVLEV ◽  
A. GREILICH ◽  
M. BAYER ◽  
I. A. YUGOVA
Keyword(s):  
Quantum Dots ◽  
Electron Spin ◽  
Zeeman Splitting ◽  
Mode Locking ◽  
Spin Coherence ◽  
Time Resolved ◽  
Pump Probe ◽  
Spin Dephasing ◽  
Rotation Technique ◽  
Singly Charged

Electron spin coherence is examined experimentally and theoretically in singly charged ( In , Ga ) As / GaAs quantum dots. Time-resolved pump-probe Faraday rotation technique is used to examine fine structure and Zeeman splitting of excitons and resident electrons. Spin dephasing and spin coherence times of resident electrons have been measured in the regime of mode-locking of spin coherency.

TIME-RESOLVED STUDY OF PHONON-POLARITONS IN LiTaO3 AT ROOM TEMPERATURE

1993 ◽  
Vol 07 (12) ◽  
pp. 797-811
Author(s):  
S. HUNSCHE ◽  
H.J. BAKKER ◽  
H. KURZ
Keyword(s):  
Room Temperature ◽  
Quantitative Description ◽  
Low Frequency ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Precise Determination ◽  
Time Resolved ◽  
Dispersion Branch ◽  
Phase Sensitive ◽  
Phonon Polaritons

We present a time-resolved study of phonon-polaritons in the ferroelectric LiTaO 3 at room temperature. The coherent generation and phase-sensitive detection of polaritons, using femtosecond Laser pulses, allow precise determination of polariton frequencies and dephasing times. The experimental data clearly show a resonance at 0.95 THz that has not been found in previous IR and Raman studies. The simultaneous coherent excitation of polaritons in the upper and the lower dispersion branch associated with this resonance leads to the observation of phonon-polariton beats, A quantum-mechanical model of the lowest A 1 lattice vibration in LiTaO 3 is developed, which provides a quantitative description of the low-frequency dielectric response, including the polariton dispersion and dephasing. Within this model, the transition at 0.95 THz can be identified as a classically forbidden tunneling resonance.

scholarly journals Room-Temperature Electron Spin Dynamics in Free-Standing ZnO Quantum Dots

2007 ◽  
Vol 98 (18) ◽  
Author(s):  
William K. Liu ◽  
Kelly M. Whitaker ◽  
Alyssa L. Smith ◽  
Kevin R. Kittilstved ◽  
Bruce H. Robinson ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Spin ◽  
Room Temperature ◽  
Spin Dynamics ◽  
Free Standing ◽  
Temperature Electron ◽  
Zno Quantum Dots ◽  
Electron Spin Dynamics
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