Z-contrast scanning transmission electron microscopy on self-assembled CdSe quantum dots in ZnSe and (Zn,Mn)Se matrices

Teya Topuria, Peter Möck, Nigel D. Browning, Lubov V. Titova, Malgorzata Dobrowolska, Sanghoon Lee, Jacek K. Furdyna

Research output: Contribution to journalConference article

1 Citation (Scopus)

Abstract

Z-contrast imaging in the scanning transmission electron microscope (STEM) was employed to study single and multi-sheet arrangements of self-assembled CdSe quantum dots (QDs) in ZnSe and (Zn0.9Mn0.1)Se matrices. The negligible influence of strain field on Z-contrast images allow for an analysis of the shapes and sizes of a large number of QDs. Higher levels of self-ordering could be proven by such analyses in a sample for which a fractional monolayer of MnSe was deposited prior to the deposition of a single CdSe sheet, that subsequently self-assembled into three dimensional (3D) quantum dots. In the multi-sheet structure, we observed the co-existence of a variety of differently shaped, sized, and self-ordered Cd rich agglomerates. Several of these agglomerates showed different types of compositional modulation on the atomic scale. The advantages of using atomic resolution Z-contrast imaging in STEM for the elucidation of these modulations are demonstrated. Results of the standardless qualitative elemental mapping technique of Z-contrast STEM are in agreement with the results of semi-quantitative energy dispersive X-ray spectroscopy (EDS).

Original languageEnglish
Pages (from-to)J8.3.1-J8.3.6
JournalMaterials Research Society Symposium - Proceedings
Volume642
Publication statusPublished - 2001 Dec 1
EventSemiconductor Quantum Dots II - Boston, MA, United States
Duration: 2000 Nov 272000 Nov 30

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Topuria, T., Möck, P., Browning, N. D., Titova, L. V., Dobrowolska, M., Lee, S., & Furdyna, J. K. (2001). Z-contrast scanning transmission electron microscopy on self-assembled CdSe quantum dots in ZnSe and (Zn,Mn)Se matrices. Materials Research Society Symposium - Proceedings, 642, J8.3.1-J8.3.6.