Copper migration and surface oxidation of CuxBi2Se3 in ambient pressure environments
Abstract
Chemical modifications such as intercalation can be used to modify surface properties or to further functionalize the surface states of topological insulators (TIs). Using ambient pressure x-ray photoelectron spectroscopy, we report copper migration in C u x B i 2 S e 3 , which occurs on a timescale of hours to days after initial surface cleaving. The increase in near-surface copper proceeds along with the oxidation of the sample surface and large changes in the selenium content. These complex changes are further modeled with core-level spectroscopy simulations, which suggest a composition gradient near the surface which develops with oxygen exposure. Our results shed light on a new phenomenon that must be considered for intercalated TIs—and intercalated materials in general—that surface chemical composition can change when specimens are exposed to ambient conditions.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 01, 2022
- Source ID
- 10.1088/2515-7639/ac93b5
Entities
People
- Adam L. Gross
- David M Nisson
- Inna Vishik
- Kristie J Koski
- Lorenz Frevel
- Matthew Staab
- Metzli I Montero
- Nicholas J Curro
- Peter Klavins
- Rahim R. Ullah
- Slavomir Nemsak
- Valentin Taufour
Organizations
- Air Force Office of Scientific Research
- Alfred P. Sloan Foundation
- National Science Foundation
- United States Department of Energy
- University of California