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Temperature dependence of the photoluminescence of self-assembled InAs/GaAs quantum dots studied in high magnetic fields.

Research output: Contribution to journalJournal article

Published

  • Thomas Nuytten
  • Manus Hayne
  • Mohamed Henini
  • Victor V. Moshchalkov
Journal publication date03/2009
JournalMicroelectronics Journal
Journal number3
Volume40
Number of pages3
Pages486-488
Original languageEnglish

Abstract

We have investigated the photoluminescence (PL) of self-assembled InAs/GaAs quantum dots (QDs) in high magnetic fields of up to 50 T and as a function of temperature. Our data clearly indicate that two different mechanisms are at work. At low temperatures (T < 80 K), the zero-field PL is increasingly dominated by lower energy dots. High-field measurements however demonstrate that these dots are larger in size only in the growth direction. At temperatures above 100 K, a strong decrease of the PL peak energy shift with field is observed, while the zero-field PL is characterized by a redshift according to the changes in the bandgap. We discuss these contradictory observations in terms of a phenomenon that we call field-assisted enhancement of the QD barrier potential. Since this effect is much stronger for small high-energy QDs, the latter progressively dominate the PL emission when temperature and magnetic field are increased.

Bibliographic note

The final, definitive version of this article has been published in the Microelectronics Journal, 40 (3), 2009, © ELSEVIER.