Improved electronic structure prediction of chalcopyrite semiconductors from a semilocal density functional based on Pauli kinetic energy enhancement factor

TL;DR

This paper demonstrates that a meta-GGA density functional based on the Pauli kinetic energy enhancement factor improves electronic structure predictions of chalcopyrite semiconductors, matching hybrid methods at lower computational cost.

Contribution

The study introduces the use of the MGGAC functional with the Pauli kinetic energy enhancement factor for better electronic property predictions of chalcopyrites.

Findings

MGGAC functional yields bandgaps comparable to hybrid methods.

Inclusion of the Pauli kinetic energy enhancement factor improves d electron treatment.

Method offers a computationally efficient alternative for solid-state systems.

Abstract

The correct treatment of d electrons is of prime importance in order to predict the electronic properties of the prototype chalcopyrite semiconductors. The effect of d states is linked with the anion displacement parameter u, which in turn influences the bandgap of these systems. Semilocal exchange-correlation functionals which yield good structural properties of semiconductors and insulators often fail to predict reasonable u because of the underestimation of the bandgaps arising from the strong interplay between d electrons. In the present study, we show that the meta-generalized gradient approximation (meta-GGA) obtained from the cuspless hydrogen density (MGGAC) [Phys. Rev. B 100, 155140 (2019)] performs in an improved manner in apprehending the key features of the electronic properties of chalcopyrites, and its bandgaps are comparative to that obtained using state-of-art hybrid methods. Moreover, the present assessment also shows the importance of the Pauli kinetic energy enhancement factor, $\alpha=(\tau-\tau^W)/\tau^{unif}$ in describing the d electrons in chalcopyrites. The present study strongly suggests that the MGGAC functional within semilocal approximations can be a better and preferred choice to study the chalcopyrites and other solid-state systems due to its superior performance and significantly low computational cost.