Electrostatic force analysis, optical measurements, and structural characterization of zinc oxide colloidal quantum dots synthesized by sol-gel method
Abstract
ZnO quantum dots (QDs) are used in a variety of applications due to several desirable characteristics, including a wide band gap, luminescence, and biocompatibility. Wurtzite ZnO QDs also exhibit a spontaneous polarization along the growth axis, leading to large electric fields. In this work, ZnO QDs around 7 nm in diameter are synthesized using the sol-gel method. Their size and structure are confirmed using photoluminescence, Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. Additionally, electrostatic force microscopy (EFM) is used to measure the amplitude change in the probe which is associated with the electric field produced by ZnO immobilized by layer-by-layer synthesis technique. The measured electrostatic field of 108 V/m is comparable to theoretically predicted value. Additionally, the strength of the electrostatic field is shown to depend on the orientation of the QD's c-axis. These results demonstrate a unique technique of quantifying ZnO's electric force using EFM.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 18, 2015
- Source ID
- 10.1063/1.4935948
Entities
People
- Leigha Covnot
- Michael A. Stroscio
- Min S. Choi
- Mitra Dutta
- Samuel Doan
- Sidra Farid
- Souvik Mukherjee
- Xenia Meshik
Organizations
- Army Research Office
- National Science Foundation
- University of Illinois at Chicago