Impact of delta-doping position on photoluminescence in type-II InAs/GaAsSb quantum dots

Yeongho Kim, Keun Yong Ban, Darius Kuciauskas, Patricia C. Dippo, Christiana Honsberg

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

We studied the optical properties of InAs/GaAs0.83Sb0.17 quantum dots (QDs), with varying silicon delta-doping position (spatial distance, d=0.5, 1, and 2 nm), using photoluminescence (PL) measurements. Compared with the undoped QDs, the PL peak energies of the ground state (GS) emissions for the doped QDs with d=0.5 and 2 nm were found to be greatly blueshifted by ∼31 meV, which was much larger than that for the doped QDs with d=1 nm. The radiative recombination rate of the GS emissions for the doped QDs with d=1 nm was estimated to be slower than that for the other doped QDs at 10 K. The doped QDs with d=1 nm showed the fastest redshift of the GS peak energy with temperature and lowest thermal activation energy (151 meV) of electrons among the QD samples. Further, the time-resolved PL data revealed that the average carrier lifetime (6.3 ns) in the doped QDs with d=1 nm was longer even than that in the undoped QDs (5.5 ns) because of the weakened electron-hole wavefunction overlap by the V-shaped potential barrier in the doped QDs.

Original languageEnglish (US)
Article number035006
JournalSemiconductor Science and Technology
Volume30
Issue number3
DOIs
StatePublished - Mar 1 2015

Keywords

  • InAs/GaAsSb
  • delta-doping
  • intermediate band solar cells
  • molecular beam epitaxy
  • quantum dots

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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