Effect of excitons in AlGaAs/GaAs superlattice solar cells

Jiro Nishinaga*, Atsushi Kawaharazuka, Koji Onomitsu, Klaus H. Ploog, Yoshiji Horikoshi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


The effect of excitonic absorption on solar cell efficiency has been investigated using solar cells with AlGaAs/GaAs superlattice active regions. Numerical calculations reveal that excitonic absorption considerably enhances the overall absorption of bulk GaAs. Excitonic absorption shows strong and sharp peaks at the absorption edge and in the energy region above the band gap. Absorption enhancement is also achieved in the AlGaAs/GaAs superlattice. The measured quantum efficiency spectra of AlGaAs/GaAs solar cells are found to be quite similar to the calculated absorption spectra considering the excitonic effect. The miniband structures of the superlattice and the electric field of the p-i-n junction enhance the dissociation of excitons and the extraction of separated carriers. These results suggest that the enhanced absorption by excitons can increase the quantum efficiency of solar cells.

Original languageEnglish
Article number052302
JournalJapanese Journal of Applied Physics
Issue number5 PART 1
Publication statusPublished - 2011 May

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


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