Femtosecond measurement of electron capture and intersubband relaxation in self-organized InAs quantum wires onIn1−xAlxAs/InP

2001 ◽  
Vol 63 (8) ◽  
Author(s):  
E. Péronne ◽  
T. Polack ◽  
J. F. Lampin ◽  
F. Fossard ◽  
F. Julien ◽  
...  
1996 ◽  
Vol 53 (8) ◽  
pp. R4225-R4228 ◽  
Author(s):  
J. F. Ryan ◽  
A. C. Maciel ◽  
C. Kiener ◽  
L. Rota ◽  
K. Turner ◽  
...  

1996 ◽  
Vol 422 ◽  
Author(s):  
M. R. Bennett ◽  
K. E. Singer ◽  
A. C. Wright ◽  
Z. H. Jafri

AbstractThe growth of epitaxial GaAs doped with the rare earth thulium (Tm) by MBE is reported for the first time. The nature of the incorporation of Tm has been studied using SIMS, RBS, TEM, PL and DCXRD. Sharp doping profiles have been observed by SIMS from samples doped in a staircase structure. Under standard GaAs growth conditions, TEM has revealed a solubility limit of ∼5×1019cm−3, above which Tm precipitates as spherical nano-particles of uniform size (1.3–1.7nm). High resolution TEM has provided no evidence for strain relaxation around these precipitates. Growth at higher substrate temperatures (≥620°C) or at As:Ga ratios close to stoichiometry, results in the formation of precipitate wires and/or bifurcated structures (“quantum trees”) aligned approximately in the direction of growth. Such behaviour is in common with that of Er in GaAs and suggests that the precipitates result from the self-organised growth of TmAs. Mechanisms for the formation of the quantum wires and trees are suggested. Initial photoluminescence spectra from these samples show two groups of narrow Tm3+ intra 4f transition lines corresponding to the 3H5 – 3H6 (∼1.01eV/1.2μm) and 3H4 – 3H6 (∼ 0.71eV/1.7μm) transitions. The spectra exhibit an excellent correlation with those obtained from samples grown by MOVPE and also those implanted with Tm by other groups.


2006 ◽  
Vol 88 (12) ◽  
pp. 123104 ◽  
Author(s):  
Yuan-li Wang ◽  
P. Jin ◽  
X. L. Ye ◽  
C. L. Zhang ◽  
G. X. Shi ◽  
...  

2001 ◽  
Vol 707 ◽  
Author(s):  
H.R. Gutiérrez ◽  
M.A. Cotta ◽  
M.M.G. de Carvalho

ABSTRACTIn this letter we report the transition from self-assembled InAs quantum-wires to quantum-dots grown on (100) InP substrates. This transition is obtained when the wires are annealed at the growth temperature. Our results suggest that the quantum-wires are a metastable shape originated from the anisotropic diffusion over the InP buffer layer during the formation of the first InAs monolayer. The wires evolve to a more stable shape (dot) during the annealing. The driving force for the transition is associated with variations in the elastic energy and hence in the chemical potential produced by height fluctuations along the wire. The regions along the wires with no height variations are more stable allowing the formation of complex, self-assembled nanostructures such as dots interconnected by wires.


2005 ◽  
Vol 2 (8) ◽  
pp. 3072-3076
Author(s):  
S. Ishida ◽  
K. Takeda ◽  
H. Tokumon ◽  
S. Shimomura ◽  
S. Hiyamizu

2009 ◽  
Vol 79-82 ◽  
pp. 1707-1710
Author(s):  
Ling Min Kong ◽  
Cun Xi Zhang ◽  
Rui Wang ◽  
Shi Lai Wang

Self –organized InAs quantum wires (QWRs) were fabricated on the step edges of GaAs (331)A surface by molecular beam epitaxy (MBE). The atomic force microscopy (AFM) results show that the lateral size of InAs QWRs is 90 nm while the size along the step lines increasing with the thicknesses of InAs layers, amounting to 1100nm. The height of InAs QWRs varies from 7.9nm to 13nm. Photoluminescence (PL) measurements on the two samples were explored and an obvious PL peak around 967 nm was observed at 25 K. The PL intensity decreases as the temperature increases, and it will vanish above 60 K. However, the QWR sample with thicker InAs layer emits a long emission of 1100 nm -1400 nm as the temperature rises above 50 K, and a longer emission of 1400-1600nm as the temperature approaches to 100 K. We considered that the complex photoluminescence spectra were originated from the multiple energy steps. The carrier migration among the different QWRs structures intensified with temperature, and the chance rate from the higher energy levels to the lower ones which generated a stronger emission of long wavelength. The carrier dynamics of QWR samples were measured by using time resolved PL (TRPL) spectra from 25 K to 100 K. The PL decay time in the QWR structure at longer emission was found to be independent of the temperature as T<100 K, showing a typical dynamical behavior of the localized excitons.


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