Small polaron-related recombination in BaxSr1−xTiO3 thin films by cathodoluminescence spectroscopy

Abstract

Polarons are critical to our understanding of many condensed matter systems, but are difficult to observe and characterize. By combining cathodoluminescence spectroscopy measurements with insights from first-principles calculations, we have identified transitions involving two distinct and simultaneous polaronic states in relaxed BaxSr1−xTiO3 films grown by molecular beam epitaxy. These polaronic optical transitions arise from two discrete Ti-O-Ti bonding configurations simultaneously present in the system, one with a 180° bond angle and the other with buckled geometry due to octahedral tilting. By compositional modulation, we show that we can semi-quantitatively probe the population of each bonding configuration.

Document Details

Document Type
Pub Defense Publication
Publication Date
Mar 07, 2016
Source ID
10.1063/1.4943191

Entities

People

  • Adam J. Hauser
  • Adam P. Kajdos
  • Anderson Janotti
  • Evgeny Mikheev

Organizations

  • Army Research Office
  • National Science Foundation
  • University of Alabama
  • University of California
  • University of Delaware

Tags

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Quantum Chemistry
  • Semiconductor Device Technology