Eur. Phys. J. Appl. Phys. 88, 10501 (2019)
https://doi.org/10.1051/epjap/2019190178

Regular Article

Band gap modulation effect on electronic and optical properties in PbTiO₃ under stress: a DFT study

¹ Department of Physics, University of Gujrat, Gujrat 50700, Pakistan
² School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, P.R. China
³ Department of Physics, Government College Women University, Sialkot, Pakistan
⁴ Department of Basic Sciences and Humanities, University of Engineering and Technology Lahore (Narowal Campus), Lahore, Pakistan
⁵ Department of Physics, Government College University Lahore, Lahore 54000, Pakistan
⁶ Department of Physics, University of Education DG Khan Campus, DG Khan, Pakistan
⁷ CHEP, University of the Punjab, Punjab 54590, Pakistan

^* e-mail: dr.rizwan@uog.edu.pk

Received: 28 May 2019
Received in final form: 19 September 2019
Accepted: 14 October 2019
Published online: 17 December 2019

Abstract

First principles calculation was implemented to explore the effect of band gap modulation under stress in cubic PbTiO₃ by using generalized gradient approximation (GGA) and ultrasoft pseudo-potential (USP). The band gaps at different external pressures show indirect band nature with significant reduction in band gapes. The density of states indicated that the upper valence states were influenced by O-2p and in the meantime Ti-d states have main contribution in conduction band. The inclusion of external stress not only changes electronic structure but also significantly changes the optical properties such as complex dielectric function, absorption, energy loss function, refractive index and reflectivity. The shifting of absorption edges toward higher energies confirm the presence of blue shift and make this material an appealing candidate for optoelectronic devices.