Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
Strain-balanced type-II superlattices for efficient multi-junction solar cells
Research Areas
  • Electronic technology and of the communications
Multi-junction solar cells made by assembling semiconductor materials with different bandgap energies have hold the record conversion efficiencies for many years and are currently approaching 50 %. Theoretical efficiency limits make use of optimum designs with the right lattice constant-bandgap energy combination, which requires a 1.0-1.15 eV material lattice-matched to GaAs/Ge. Nevertheless, the lack of suitable semiconductor materials is hindering the achievement of the predicted efficiencies, since the only candidates were up to now complex quaternary and quinary alloys with inherent epitaxial growth problems that degrade carrier dynamics. Here we show how the use of strain-balanced GaAsSb/GaAsN superlattices might solve this problem. We demonstrate that the spatial separation of Sb and N atoms avoids the ubiquitous growth problems and improves crystal quality. Moreover, these new structures allow for additional control of the effective bandgap through the period thickness and provide a type-II band alignment with long carrier lifetimes. All this leads to a strong enhancement of the external quantum efficiency under photovoltaic conditions with respect to bulk layers of equivalent thickness. Our results show that GaAsSb/GaAsN superlattices with short periods are the ideal (pseudo)material to be integrated in new GaAs/Ge-based multi-junction solar cells that could approach the theoretical efficiency limit.
Scientific Reports
Impact factor JCR
Impact info
Datos JCR del año 2015
Journal number
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  • Autor: Alicia Gonzalo Martin (UPM)
  • Autor: Antonio David Utrilla Lomas (UPM)
  • Autor: Daniel F. Reyes (UCA)
  • Autor: Verónica Braza (UCA)
  • Autor: José M. Llorens (IMM)
  • Autor: David F. Marrón (IES)
  • Autor: Benito Alén (IMM)
  • Autor: Teresa Ben (UCA)
  • Autor: David González (UCA)
  • Autor: Alvaro de Guzman Fernandez Gonzalez (UPM)
  • Autor: Adrian Hierro Cano (UPM)
  • Autor: Jose Maria Ulloa Herrero (UPM)
Research Group, Departaments and Institutes related
  • Creador: Departamento: Ingeniería Electrónica
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)