InGaAs embedding of large InAs quantum dots obtained by pulsed in deposition for long-wavelength applications

Abstract

In this work we studied the molecular-beam epitaxy of large InAs quantum dots embedded in an InGaAs quantum well. The formation of the quantum dots was performed by pulsed deposition of InAs material, simulating therefore a low deposition rate. Room-temperature photoluminescence experiments carried out on these samples showed intense emissions with a wavelength exceeding 1.35µm. Our preliminary data indicate that even better results can be achieved by further manipulation of the growth conditions.

Optical probe of InAs/GaAs self-assembled quantum dots grown using low growth rate and growth interruptions

“…1.8 ML of InAs were initially deposited to favor the formation of a low islands density [9,13,15]. Then, in order to cause red shift of the dots emission wavelength, enhance their shape uniformity and optical properties as well [13,14], extra 0.6 ML was supplied over five growth cycles to reach 2.4 ML of InAs total coverage. Each growth cycle consisted of a 30 s growth interrupt (In cell shutter closed) followed by $8.6 s of InAs deposition.…”

“…By optimizing the growth parameters and barrier layers structure [7][8][9][10], it is possible to control the uniformity of the nanostructures morphology, their density, as well as their optical emission energy and linewidth. Growth interruptions (GI) [11][12][13][14] and ultra-low growth rates [15,16] have also been used to tune the dots emission, improve their size distribution or significantly reduce their density, which is particularly interesting for single dot spectroscopy.…”

Desarrollo de dispositivos optoelectrónicos mediante crecimiento por MBE y caracterización de nanoestructuras de punto cuántico basadas en (Ga,In)(As,N)

“…Por ello, el beneficio del redshift alcanzado con los QDs de mayores dimensiones conseguidos mediante el crecimiento a tan bajas velocidades de crecimiento, es parcialmente perdido debido a la intensificación de la segregación con el crecimiento también a tan bajas velocidades del capping de InGaAs. Alguno de los métodos adicionales que nos encontramos en la literatura para intentar subsanar este problema es el crecimiento de QDs utilizando interrupciones en el crecimiento [Lam06][Kir02], aunque aún así se sigue perdiendo todavía parte del redshift conseguido.…”