Tin monochalcogenide heterostructures as mechanically rigid infrared bandgap semiconductors

TL;DR

This study demonstrates that SnS and SnSe heterostructures are mechanically rigid and possess tunable infrared bandgaps, with potential applications in optoelectronics, achieved through first-principles calculations and strain engineering.

Contribution

It reveals the mechanical rigidity and electronic properties of SnS/SnSe heterostructures, highlighting their potential for infrared applications and strain-induced bandgap tuning.

Findings

Heterostructures are mechanically rigid with delocalized electronic wavefunctions.

Bandgaps are in the infrared region and can be tuned via strain.

Strain induces a transition from indirect to direct bandgap.

Abstract

Based on first-principles density functional calculations, we show that SnS and SnSe layers can form mechanically rigid heterostructures with the constituent puckered or buckled monolayers. Due to the strong interlayer coupling, the electronic wavefunctions of the conduction and valence band edges are delocalized across the heterostructure. The resultant bandgap of the heterostructures reside in the infrared region. With strain engineering, the heterostructure bandgap undergoes transition from indirect to direct in the puckered phase. Our results show that there is a direct correlation between the electronic wavefunction and the mechanical rigidity of the layered heterostructure.