Strain-balanced type-II superlattices for efficient multi-junction solar cells

Gonzalo Martín, Alicia and Utrilla Lomas, Antonio David and Reyes, D.F. and Braza Blanco, Verónica and Llorens, J.M. and Fuertes Marrón, David and Alén, B. and Ben, T. and González, D. and Fernández González, Alvaro de Guzmán and Hierro Cano, Adrián and Ulloa Herrero, José María (2017). Strain-balanced type-II superlattices for efficient multi-junction solar cells. "Scientific Reports", v. 7 (n. 4012); pp. 1-10. ISSN 2045-2322.


Title: Strain-balanced type-II superlattices for efficient multi-junction solar cells
  • Gonzalo Martín, Alicia
  • Utrilla Lomas, Antonio David
  • Reyes, D.F.
  • Braza Blanco, Verónica
  • Llorens, J.M.
  • Fuertes Marrón, David
  • Alén, B.
  • Ben, T.
  • González, D.
  • Fernández González, Alvaro de Guzmán
  • Hierro Cano, Adrián
  • Ulloa Herrero, José María
Item Type: Article
Título de Revista/Publicación: Scientific Reports
Date: June 2017
ISSN: 2045-2322
Volume: 7
Faculty: Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM) (UPM)
Department: Otro
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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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 1.0–1.15eV 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.

Funding Projects

Government of SpainMAT2013-47102-C2-2-RUnspecifiedJosé María Ulloa HerreroAleaciones emergentes de nitruros diluidos III-V y nanoestructuras relacionadas para aplicaciones fotovoltaicas y de fotodetección de alta eficiencia.
Government of SpainMAT2016-77491-C2-1-RUnspecifiedJosé María Ulloa HerreroNuevas nanoestructuras basadas en SB para aplicaciones fotovoltaicas de alta eficiencia
Government of SpainTEC2015-64189-C3-2-RUnspecifiedUnspecifiedInvestigación, desarrollo e innovación en nuevas estructuras de células solares para alta eficiencia de conversión fotovoltaica. Subproyecto 2
Madrid Regional GovernmentS2013/MAE-2780MADRID-PVUnspecifiedMateriales, dispositivos y tecnología para el desarrollo de la industria fotovoltaica
Government of SpainAIC-B_2011-0806UnspecifiedJorge M. GarcíaColaboración IMM-CSIC con INL en desarrollo de instrumentación para procesos de recubrimientos especiales en sensores

More information

Item ID: 50100
DC Identifier:
OAI Identifier:
DOI: 10.1038/s41598-017-04321-4
Official URL:
Deposited by: Memoria Investigacion
Deposited on: 07 Nov 2021 10:27
Last Modified: 07 Nov 2021 10:27
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