Modulating the electronic and optical properties of a ternary chalcogenide CdTl2Te4 via external electric field: A DFT study

TL;DR

This study uses DFT calculations to explore how an external electric field can modulate the electronic and optical properties of the ternary chalcogenide CdTl2Te4, revealing potential for optoelectronic applications.

Contribution

It provides the first detailed analysis of how external electric fields influence the electronic structure and optical properties of CdTl2Te4 using first principles calculations.

Findings

Energy gap increases with electric field perpendicular to xy plane.

Optical properties are significantly modulated for out-of-plane polarized light.

Potential applications in UV absorption and solar cells are identified.

Abstract

Various ternary chalcogenide systems and their properties are one of the hot topics for researchers nowadays. In this article, one of the ternary chalcogenide compounds, CdTl2Te4 is studied including its electronic structures and optical properties via first principles calculations using SIESTA code. The structure of the compound has a tetragonal crystal system and the unit cell is periodic in all directions. The band structure showed it is a direct band gap semiconductor which is explained by the density of states. The energy gap obtained is seen to increase on employing external electric field perpendicular to the xy plane, but does not increase on increasing the magnitude of field strength. The optical properties which includes absorption coefficient, reflectance, real & imaginary parts of dielectric function, refractive index and extinction coefficient were calculated for polarized light both in plane and out of the plane, but the interesting modulation in properties were seen for the latter which can open up applications of the compound in UV absorbers, making solar cells, etc. So, the compound being a narrow-gap semiconductor along with its tunable electronic and optical properties can have potential application in the fields such as optoelectronics.