Materials Science and Engineering
In this work, we demonstrate that the optical bandgap of WO3 films can be continuouslycontrolled through uniaxial strain induced by low-energy helium implantation.The insertion of He into epitaxially grown and coherently strained WO3 films canbe used to induce single axis out-of-plane lattice expansion of up to 2%. Ellipsometricspectroscopy reveals that the optical bandgap is reduced by about 0.18 eVper percent expansion of the out-of-plane unit cell length. Density functional theorycalculations show that this response is a direct result of changes in orbital degeneracydriven by changes in the octahedral rotations and tilts.
Andreas Herklotz, Stefania Rus, Santosh KC, Valentino Cooper, Amanda Huon, Er-Jia Guo, and Thomas Ward. "Symmetry driven control of optical properties in WO3 films" APL Materials (2017). https://doi.org/10.1063/1.4989395
SJSU users: Use the following link to login and access the article via SJSU databases.This article was published in APL Materials, volume 5, issue 6, 2017, and can also be found online here.