Space-charge effects in type-II strained layer superlattices

I.V. Bradley, J.P. Creasey, K. P. O'Donnell

Research output: Contribution to journalArticle

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Abstract

The low-temperature photoluminescence (PL) spectra of a range of CdS-CdSe and CdS-ZnSe type-II superlattices was measured under both cw and quasi-cw excitation over the excitation range from mW cm-2 to MW cm-2. In all cases, a single PL band due to the recombination of separated electrons and holes in the type-II bandstructure was observed. As the excitation density increases from a low value, the PL peak shifts logarithmically towards the blue. Total shifts of up to 200 meV for a CdS-CdSe sample of 10 nm period are observed, with a corresponding shift-factor of 30 meV per decade of excitation density. The shift factor increases in a regular fashion with the superlattice period. A comparison with the literature shows that a logarithmic dependance of the blue shift with increasing excitation density appears to be a universal feature of type-II SL, even in the absence of strain.

LanguageEnglish
Pages728-731
Number of pages4
JournalJournal of Crystal Growth
Volume184-185
DOIs
Publication statusPublished - 2 Feb 1998

Fingerprint

Superlattices
Electric space charge
superlattices
space charge
Photoluminescence
excitation
shift
photoluminescence
blue shift
Electrons
Temperature
electrons

Keywords

  • superlattices
  • photoluminescence
  • strained layer superlattice

Cite this

Bradley, I.V. ; Creasey, J.P. ; O'Donnell, K. P. / Space-charge effects in type-II strained layer superlattices. In: Journal of Crystal Growth. 1998 ; Vol. 184-185. pp. 728-731.
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Space-charge effects in type-II strained layer superlattices. / Bradley, I.V.; Creasey, J.P.; O'Donnell, K. P.

In: Journal of Crystal Growth, Vol. 184-185, 02.02.1998, p. 728-731.

Research output: Contribution to journalArticle

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