Investigation of Copper(I) Oxide Quantum Dots by Near-Edge X-ray-Absorption Fine-Structure Spectroscopy

Document Type

Article

Publication Date

10-2003

Publication Title

Chemistry of Materials

Volume

15

Issue

20

First page number:

3939

Last page number:

3946

Abstract

Copper(I) oxide quantum dots (OQDs) were grown in various thicknesses on different SrTiO3(001) surfaces and were investigated by near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The experimental growth conditions for the OQDs were optimized to obtain Cu2O as the major phase. The OQDs grown on clean SrTiO3(001) surfaces at 825 K and higher with p(O2) of 9.0 × 10-7 Torr or greater contain mostly CuO, contrasting to OQDs grown at 800 K with p(O2) of 7.0 × 10-7 Torr that contain primarily Cu2O. Furthermore, there is a strong interaction between the SrTiO3(001) surface and the first few monolayers of the OQDs, which induces the formation of Cu(II). However, this interaction is mitigated with increasing thickness of OQDs, resulting in the exclusive formation of Cu2O in the topmost layers. The influence of the SrTiO3(001) substrate on the formation of OQDs can be minimized by modifying the substrate surface using chemical treatment and/or energetic Au2+ ion-beam irradiation. Examination of the photochemical properties of these OQDs shows that prolonged soft X-ray irradiation under vacuum reduces Cu(II), which is present as a minor impurity in the Cu(I) OQDs.

Keywords

Copper oxide; Quantum dots; Strontium compounds; X-ray Absorption Near Edge Structure

Disciplines

Analytical Chemistry | Atomic, Molecular and Optical Physics | Biological and Chemical Physics | Elementary Particles and Fields and String Theory | Physical Chemistry

Language

English

Permissions

Use Find in Your Library, contact the author, or use interlibrary loan to garner a copy of the article. Publisher copyright policy allows author to archive post-print (author’s final manuscript). When post-print is available or publisher policy changes, the article will be deposited

UNLV article access

Search your library

Share

COinS