Transmission Electron Microscopy of ZnSe/CdSe Heterostructure Nanowires

Open Access
Author:
Williams, Krystaufeux Dormas
Graduate Program:
Materials Science and Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 08, 2010
Committee Members:
  • Nitin Samarth, Thesis Advisor
Keywords:
  • transmission electron microscopy
  • ZnSe
  • CdSe
  • heterostructures
  • nanowires
  • molecular beam epitaxy
Abstract:
Instabilities in the form of kinking (via incoherency across the interface) can occur during growth of heterostructure nanowires (hNWs) by molecular beam epitaxy (MBE). Furthermore, the challenge remains to create hNWs with controlled diameters, composition and morphology. ZnSe/CdSe NWs were grown in an EPI 620 MBE system equipped with low temperature effusion cells. Transmission electron microscopy was used to characterize the heterostructures and to suggest a means of fixing these issues. HNWs were studied over temperature and diameter ranges from 415-475°C and 10-25 nm, respectively. It was observed that a linear relationship may exist between the occurrence of kinks in hNWs and the CdSe layer thickness and diameter.