Memorias de investigación
Ponencias en congresos:
InAs/AlGaAs quantum dot intermediate band solar cells with enlarged sub-bandgaps
Año:2012
Áreas de investigación
  • Ingeniería eléctrica, electrónica y automática,
  • Dispositivos electrónicos,
  • Células solares,
  • Tecnología de dispositivos para ingeniería eléctrica y electrónica
Datos
Descripción
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.
Internacional
Si
Nombre congreso
38th IEEE Photovoltaic Specialists Conference
Tipo de participación
960
Lugar del congreso
Austin (TE) EEUU
Revisores
Si
ISBN o ISSN
0160-8371
DOI
10.1109/pvsc.2012.6317694
Fecha inicio congreso
03/06/2012
Fecha fin congreso
08/06/2012
Desde la página
652
Hasta la página
656
Título de las actas
Proc. 38th IEEE PVSC
Esta actividad pertenece a memorias de investigación
Participantes
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Silicio y Nuevos Conceptos para Células Solares
  • Centro o Instituto I+D+i: Instituto de Energía Solar
  • Departamento: Electrónica Física