Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
Influence of Sb/N contents during the capping process on the morphology of InAs/GaAs quantum dots
Year:2016
Research Areas
  • Electronic technology and of the communications
Information
Abstract
InAs/GaAs QDs are being investigated in the field of solar cells (SCs) with the aim of achieving high SC performances. In order to control the band offsets and the accumulated strain, the application of capping layers (CLs) made of GaAs-based alloys is becoming a common approach that shows promising advantages for SC applications. However, up to now there are very few statistically reliable studies of their impact on the QD morphologies. Our work by TEM techniques over more than a hundred of InAs QDs has evaluated a broad range of CL materials and structures with Sb and/or N with a singular accuracy. Our outcomes showed that the Sb could play antagonistic roles regarding the QD decomposition depending on the growth conditions. Unlike it occurs at common growth rates (1 ML/s), at high growth rates of 2 ML/s the Sb does not protect the QDs, but even intensifies their erosion. On the other side, N provides the best results in terms of maintaining the original shape of the QDs. In the case of a simultaneous presence of Sb and N, a synergetic effect in the erosion strength is observed. Nevertheless, avoiding the concomitance presence of N and Sb on the growth front by growing a short-period GaAsSb/GaAsN superlattice CLs moderates this behavior. The results are discussed in terms of processes such as surfactant, intermixing, segregation, bond strength or strain-enhanced diffusion that could operate during the capping process. The strong modifications on the QD?CL morphology, that we show are expected to have a significant impact on QD SC performance, cannot be disregarded.
International
Si
JCR
Si
Title
Solar Energy Materials And Solar Cells
ISBN
0927-0248
Impact factor JCR
4,732
Impact info
Datos JCR del año 2015
Volume
145
10.1016/j.solmat.2015.07.015
Journal number
From page
154
To page
161
Month
SIN MES
Ranking
Participants
  • Autor: D. González (UCA)
  • Autor: D.F. Reyes (UCA)
  • Autor: T. Ben (UCA)
  • Autor: Antonio David Utrilla Lomas (UPM)
  • Autor: Jose Maria Ulloa Herrero (UPM)
  • Autor: Alvaro de Guzman Fernandez Gonzalez (UPM)
  • Autor: Adrian Hierro Cano (UPM)
Research Group, Departaments and Institutes related
  • Creador: Centro o Instituto I+D+i: Instituto Universitario de Sistemas Optoelectrónicos y Microtecnología
  • Departamento: Ciencia de Materiales
S2i 2019 Observatorio de investigación @ UPM con la colaboración del Consejo Social UPM
Cofinanciación del MINECO en el marco del Programa INNCIDE 2011 (OTR-2011-0236)
Cofinanciación del MINECO en el marco del Programa INNPACTO (IPT-020000-2010-22)