Tunable bulk photovoltaic effect in strained $\gamma$-GeSe

Abstract

Recently, Lee \textit{et. al.} [Nano Lett. \textbf{21}, 4305 (2021)] newly synthesized monochalcogenide GeSe in a polar phase, referred to as $\gamma$-phase. Motivated by this work, we study shift current of $\gamma$-GeSe and its tunability via an in-plane uniaxial strain. Using first-principles calculations, we uncover the electronic structure of the strained $\gamma$-GeSe systems. We then calculate frequency-dependent shift current conductivities at various strains. The tunability is demonstrated to enhance the shift current up to $\sim$ 20 $\mu$A/V${}^2$. Moreover, the direction of shift current can be inverted by a light strain. Markedly, an anomalous behavior is found in the zero-frequency limit, which can be an indicative of band inversion and a potential topological phase transition driven by the strain. Our results suggest that shift current can be a tangible prove of bulk electronic states of $\gamma$-GeSe.

References in corpus (7)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Surface States of the Topological Insulator Bi_{1-x}Sb_x
• Computing topological invariants without inversion symmetry
• Low-frequency divergence and quantum geometry of the bulk photovoltaic effect in topological semimetals
• γ-GeSe:a new hexagonal polymorph from group IV-VI monochalcogenides
• Phonon-Assisted Ballistic Current From First Principles Calculations
• Quasiparticle band structures, spontaneous polarization, and spin-splitting in noncentrosymmetric few-layer and bulk $\gamma$-GeSe