Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
Lattice-Mismatched 0.7-eV GaInAs solar cells grown on GaAs using GaInP compositionally graded buffers
Year:2014
Research Areas
  • Electric engineers, electronic and automatic (eil),
  • Solar cells,
  • Technology of devices for engineering
Information
Abstract
The three-junction 1.8/1.4/1.0-eV inverted metamorphic multijunction solar cell can be extended to four junctions by adding another lattice-mismatched GaInAs junction with a bandgap of 0.7 eV. However, this requires a significant amount of mismatch to GaAs substrates, i.e., 3.8%, which is difficult to obtain while maintaining high-quality material. In this paper, we perform an in-depth investigation of a GaInP compositionally graded buffer varying in composition between Ga 0.5In 0.5P and InP in order to identify limitations to dislocation glide and sources of excess dislocation formation. In situ wafer curvature, cathodoluminescence, and X-ray diffraction (XRD) are used to analyze dislocation glide; transmission electron microscopy, atomic force microscope, and XRD are used to analyze material structural properties. Composition nonuniformities and roughness are observed, and a region in the compositionally graded buffer where a significant number of excess dislocations are formed is identified. The formation of these dislocations is related to atomic ordering, which has a large influence on the dislocation behavior. Adding thickness to the region in the buffer where dislocations are formed reduces the threading dislocation density an order of magnitude. Metamorphic 0.74 eV solar cells grown on this template have internal quantum efficiency > 90% and Voc > 0.3 V with Jsc set to 13 mA/cm2, which is the expected current in a multijunction device. These results are compared with lattice-matched GaInAs/InP solar cells to evaluate the loss associated with the lattice-mismatch.
International
Si
JCR
Si
Title
Ieee Journal of Photovoltaics
ISBN
2156-3381
Impact factor JCR
3
Impact info
Volume
4
Journal number
1
From page
190
To page
195
Month
SIN MES
Ranking
Participants
  • Autor: R.M. France
  • Autor: Ivan Garcia Vara (UPM)
  • Autor: W.E. McMahon
  • Autor: A.G. Norman
  • Autor: J. Simon
  • Autor: J.F. Geisz
  • Autor: D.J. Friedman
  • Autor: M.J. Romero
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Semiconductores III-V
  • Departamento: Electrónica Física
  • Centro o Instituto I+D+i: Instituto de Energía Solar
S2i 2020 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)