Observatorio de I+D+i UPM

Memorias de investigación
Communications at congresses:
InAs/AlGaAs quantum dot intermediate band solar cells with enlarged sub-bandgaps
Year:2012
Research Areas
  • Electric engineers, electronic and automatic (eil),
  • Electronic devices,
  • Solar cells,
  • Technology of devices for engineering
Information
Abstract
In the last decade several prototypes of intermediate band solar cells (IBSCs) have been manufactured. So far, most of these prototypes have been based on InAs/GaAs quantum dots (QDs) in order to implement the IB material. The key operation principles of the IB theory are two photon sub-bandgap (SBG) photocurrent, and output voltage preservation, and both have been experimentally demonstrated at low temperature. At room temperature (RT), however, thermal escape/relaxation between the conduction band (CB) and the IB prevents voltage preservation. To improve this situation, we have produced and characterized the first reported InAs/AlGaAs QD-based IBSCs. For an Al content of 25% in the host material, we have measured an activation energy of 361 meV for the thermal carrier escape. This energy is about 250 meV higher than the energies found in the literature for InAs/GaAs QD, and almost 140 meV higher than the activation energy obtained in our previous InAs/GaAs QD-IBSC prototypes including a specifically designed QD capping layer. This high value is responsible for the suppression of the SBG quantum efficiency under monochromatic illumination at around 220 K. We suggest that, if the energy split between the CB and the IB is large enough, activation energies as high as to suppress thermal carrier escape at room temperature (RT) can be achieved. In this respect, the InAs/AlGaAs system offers new possibilities to overcome some of the problems encountered in InAs/GaAs and opens the path for QD-IBSC devices capable of achieving high efficiency at RT.
International
Si
Congress
38th IEEE Photovoltaic Specialists Conference
960
Place
Austin (TE) EEUU
Reviewers
Si
ISBN/ISSN
0160-8371
10.1109/pvsc.2012.6317694
Start Date
03/06/2012
End Date
08/06/2012
From page
652
To page
656
Proc. 38th IEEE PVSC
Participants
  • Autor: Iñigo Ramiro Gonzalez (UPM)
  • Autor: Elisa Antolin Fernandez (UPM)
  • Autor: M.J. Steer
  • Autor: Pablo Garcia-Linares Fontes (UPM)
  • Autor: Estela Hernandez Martin (UPM)
  • Autor: Irene Artacho Huertas (UPM)
  • Autor: Esther Lopez Estrada (UPM)
  • Autor: T. Ben
  • Autor: J.M. Ripalda
  • Autor: S.I. Molina
  • Autor: F. Briones
  • Autor: C.R. Stanley
  • Autor: Antonio Marti Vega (UPM)
  • Autor: Antonio Luque Lopez (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Silicio y Nuevos Conceptos para Células Solares
  • Centro o Instituto I+D+i: Instituto de Energía Solar
  • Departamento: Electrónica Física
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