Novel optical study of the tunnelling rate and ambipolar transport characteristics of excitons in superlattices with a variety of barrier thicknesses

D. J. Lovering, R. T. Phillips, R. Grey, B. Crystall, Gary Rumbles

Research output: Contribution to journalArticle


We report the use of a time-resolved transient-grating technique to study the in-plane ambipolar diffusion coefficient and interwell tunnelling probability for exctions in a number of multiple quantum well samples. Our specimens were selected with barrier thicknesses ranging from 14 to 141 A thus giving complete coverage of the transition from isolated quantum well to superlattice behaviour. Two types of MBE growth condition were used giving rise to samples with low or high surface defect density. The surface defect density had a strong effect on the in-plane mobility but not the tunnelling probability. The samples show surprisingly strong interwell coupling even with the thickest barrier. Which we attribute to defect assisted tunnelling.

Original languageEnglish
Pages (from-to)526-529
Number of pages4
JournalSemiconductor Science and Technology
Issue number5 SUPPL
Publication statusPublished - May 1994


ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Materials Science(all)
  • Electronic, Optical and Magnetic Materials

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