Strain induced bang-gap engineering in layered TiS3

Nano Research accepted, (2017)

Strain induced bang-gap engineering in layered TiS3

Robert Biele, Eduardo Flores, Jose Ramón Ares, Carlos Sanchez, Isabel J. Ferrer, Gabino Rubio-Bollinger, Andres Castellanos-Gomez, Roberto D'Agosta

By combining ab initio calculations and experiments, we demonstrate how the band gap of the transition metal tri-chalcogenide TiS3 can be modified by inducing tensile or compressive strain. In addition, from our calculations we predict that the material exhibits a transition from a direct to indirect gap when a compressive strain is applied in the direction of easy electrical transport. The ability to control the band gap and its nature can have a wide impact in the use of TiS3 for optical applications. We verify our prediction via optical absorption experiments that present a band-gap increase of up to 9% (from 0.99 to 1.08 eV) upon tensile stress application along the easy transport direction.