Influence of Strain on the Band Gap of Cu2O
Journal article, 2019

Cu2O has been considered as a candidate material for transparent conducting oxides and photocatalytic water splitting. Both applications require suitably tuned band gaps. Here we explore the influence of compressive and tensile strain on the band gap by means of density functional theory (DFT) modeling. Our results indicate that the band gap decreases under tensile strain while it increases to a maximum under moderate compressive strain and decreases again under extreme compressive strain. This peculiar behavior is rationalized through a detailed analysis of the electronic structure by means of density of states (DOS), density overlap region indicators (DORI), and crystal overlap Hamilton populations (COHP). Contrary to previous studies we do not find any indications that the band gap is determined by d10-d10 interactions. Instead, our analysis clearly shows that both the conduction and the valence band edges are determined by Cu-O antibonding states. The band gap decrease under extreme compressive strain is associated with the appearance of Cu 4sp states in the conduction band region.

Author

Alberto Visibile

University of Milan

Baochang Wang

Chalmers, Physics, Chemical Physics

Alberto Vertova

University of Milan

Sandra Rondinini

University of Milan

Alessandro Minguzzi

University of Milan

Elisabet Ahlberg

University of Gothenburg

Michael Busch

University of Gothenburg

Chemistry of Materials

0897-4756 (ISSN) 1520-5002 (eISSN)

Vol. 31 13 4787-4792

Subject Categories

Inorganic Chemistry

Other Materials Engineering

Condensed Matter Physics

DOI

10.1021/acs.chemmater.9b01122

More information

Latest update

10/29/2019