Thickness Limitation of Band-to-Band Tunneling Process in GaAsSb/InGaAs Type-II Tunnel Junctions Designed for Multi-Junction Solar Cells
Thickness Limitation of Band-to-Band Tunneling Process in GaAsSb/InGaAs Type-II Tunnel Junctions Designed for Multi-Junction Solar Cells
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DOI：
10.1021/acsaem.8b01700
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发表时间：
2019-02-01
影响因子：
6.4
通讯作者：
Almuneau, G.
中科院分区：
文献类型：
--
作者：
Louarn, K.;Claveau, Y.;Almuneau, G.
本文报道了厚度和/或组分对II型n+ InGaAs/p+ GaAsSb隧道结性能的影响。InGaAs/GaAsSb交错带偏移异质结有望改善隧穿特性。已经通过分子束外延生长具有各种厚度和/或Sb和In浓度的器件。对于薄的弹性应变II型隧道结，电特性表现出退化的传输性能相比，参考p+ GaAs/n+ GaAs隧道结结构，而更好的隧穿峰值电流实现与应变弛豫厚II型隧道结。基于对II型隧道结的局域态密度和带边轮廓的理论分析，我们提出了一种适合于具有高隧穿电流密度的II型隧道结的设计，以用于多结太阳能电池。
This article reports on the impact of the thickness and/or the composition on the performance of type-II n+ InGaAs/p+ GaAsSb tunnel junctions. The InGaAs/GaAsSb staggered band-offset heterojunction is expected to improve tunneling properties. Devices have been grown by molecular beam epitaxy with various thicknesses and/or Sb and In concentrations. For thin elastically strained type-II tunnel junctions, the electrical characteristics exhibit degraded transport performances compared to the reference p+ GaAs/n+ GaAs tunnel junction structures, while much better tunneling peak currents are achieved with strain-relaxed thick type-II tunnel junctions. Based on a theoretical analysis of the local density of states and the band-edges profiles of the type-II tunnel junctions, we propose a suitable design for type-II tunnel junctions with high tunneling current density toward their use in multi-junction solar cells.