Size, strain, and band offset engineering in GaAs(Sb)(N)-capped InAs quantum dots for 1.3 - 1.55 µm LEDs and LDs

Ulloa Herrero, José María and Moral, M. del and Montes, M. and Bozkurt, M. and Koenraad, P.M. and Fernández González, Alvaro de Guzmán and Hierro Cano, Adrián (2011). Size, strain, and band offset engineering in GaAs(Sb)(N)-capped InAs quantum dots for 1.3 - 1.55 µm LEDs and LDs. In: "SPIE Photonics West 2011", 25/01/2011 - 27/01/2011, San Francisco, CA, EEUU. pp..

Description

Title: Size, strain, and band offset engineering in GaAs(Sb)(N)-capped InAs quantum dots for 1.3 - 1.55 µm LEDs and LDs
Author/s:
  • Ulloa Herrero, José María
  • Moral, M. del
  • Montes, M.
  • Bozkurt, M.
  • Koenraad, P.M.
  • Fernández González, Alvaro de Guzmán
  • Hierro Cano, Adrián
Item Type: Presentation at Congress or Conference (Article)
Event Title: SPIE Photonics West 2011
Event Dates: 25/01/2011 - 27/01/2011
Event Location: San Francisco, CA, EEUU
Title of Book: proceecings of SPIE Photonics West 2011
Date: 2011
Subjects:
Faculty: E.T.S.I. Telecomunicación (UPM)
Department: Ingeniería Electrónica
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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Abstract

The optical and structural properties of InAs/GaAs quantum dots (QD) are strongly modified through the use of a thin (~ 5 nm) GaAsSb(N) capping layer. In the case of GaAsSb-capped QDs, cross-sectional scanning tunnelling microscopy measurements show that the QD height can be controllably tuned through the Sb content up to ~ 14 % Sb. The increased QD height (together with the reduced strain) gives rise to a strong red shift and a large enhancement of the photoluminescence (PL) characteristics. This is due to improved carrier confinement and reduced sensitivity of the excitonic bandgap to QD size fluctuations within the ensemble. Moreover, the PL degradation with temperature is strongly reduced in the presence of Sb. Despite this, emission in the 1.5 !lm region with these structures is only achieved for high Sb contents and a type-II band alignment that degrades the PL. Adding small amounts of N to the GaAsSb capping layer allows to progressively reduce the QD-barrier conduction band offset. This different strategy to red shift the PL allows reaching 1.5 !lm with moderate Sb contents, keeping therefore a type-I alignment. Nevertheless, the PL emission is progressively degraded when the N content in the capping layer is increased

More information

Item ID: 12945
DC Identifier: http://oa.upm.es/12945/
OAI Identifier: oai:oa.upm.es:12945
Deposited by: Memoria Investigacion
Deposited on: 07 Nov 2012 11:39
Last Modified: 21 Apr 2016 12:15
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