Memorias de investigación
Artículos en revistas:
Performance analysis of AlGaAs/GaAs tunnel junctions for ultra-high concentration photovoltaics
Año:2012
Áreas de investigación
  • Tecnología electrónica y de las comunicaciones
Datos
Descripción
An n(++)-GaAs/p(++)-AlGaAs tunnel junction with a peak current density of 10 100Acm(-2) is developed. This device is a tunnel junction for multijunction solar cells, grown lattice-matched on standard GaAs or Ge substrates, with the highest peak current density ever reported. The voltage drop for a current density equivalent to the operation of the multijunction solar cell up to 10 000 suns is below 5 mV. Trap-assisted tunnelling is proposed to be behind this performance, which cannot be justified by simple band-to-band tunnelling. The metal-organic vapour-phase epitaxy growth conditions, which are in the limits of the transport-limited regime, and the heavy tellurium doping levels are the proposed origins of the defects enabling trap-assisted tunnelling. The hypothesis of trap-assisted tunnelling is supported by the observed annealing behaviour of the tunnel junctions, which cannot be explained in terms of dopant diffusion or passivation. For the integration of these tunnel junctions into a triple-junction solar cell, AlGaAs barrier layers are introduced to suppress the formation of parasitic junctions, but this is found to significantly degrade the performance of the tunnel junctions. However, the annealed tunnel junctions with barrier layers still exhibit a peak current density higher than 2500Acm(-2) and a voltage drop at 10 000 suns of around 20 mV, which are excellent properties for tunnel junctions and mean they can serve as low-loss interconnections in multijunction solar cells working at ultra-high concentrations.
Internacional
Si
JCR del ISI
Si
Título de la revista
Journal of Physics D-Applied Physics
ISSN
0022-3727
Factor de impacto JCR
2,544
Información de impacto
Volumen
45
DOI
045101 10.1088/0022-3727/45/4/045101
Número de revista
4
Desde la página
45101
Hasta la página
45108
Mes
FEBRERO
Ranking
31/116 PHYSICS, APPLIED (SCI)
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Participantes
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Semiconductores III-V
  • Centro o Instituto I+D+i: Instituto de Energía Solar
  • Departamento: Electrónica Física