Optical properties of AlxGa1-xAs/GaAs superlattice solar cells

Makoto Kuramoto, Hiroyuki Urabe, Tomohiro Nakano, Atsushi Kawaharazuka, Jiro Nishinaga, Toshiki Makimoto, Yoshiji Horikoshi

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The effect of excitons in AlxGa1-xAs/GaAs superlattice solar cells has been investigated. We have shown that the superlattice active layers are effective to improve the solar cell performances because of the exciton enhanced photo-absorption. External quantum efficiency spectra show sharp and intense increase at the absorption edge due to excitonic absorption. This result indicates that excitonic photo-absorption can be stabilized at room temperature by using a superlattice structure. Optical properties of superlattice solar cells depend on the superlattice parameters because they determine the excitonic confinement effect, the tunneling effect and the sub-band structure. In this study, we compare external quantum efficiency for solar cells with different superlattice parameters to optimize the structure. The optimal barrier layer thickness is determined to be 1 nm for the Al0.5Ga0.5As/GaAs superlattice solar cell with 2-μm-thick active layer.

Original languageEnglish
Pages (from-to)333-336
Number of pages4
JournalJournal of Crystal Growth
Volume425
DOIs
Publication statusPublished - 2015 Jul 28

Keywords

  • A3. Molecular beam epitaxy
  • A3. Superlattices
  • B2. Semiconducting gallium arsenide
  • B3. Solar cells

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry

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