Strain effect of phonon and electron in 1D crystals HfS3 and ZrS3

Quasi-one-dimensional (1D) van der Waals (vdW) materials present significant potential for progressive applications owing to their unique mechanical and electronic properties, which are highly responsive to external stimuli such as strain and pressure. In this work, we investigate the thermal transport, bonding characteristics, mechanical properties, and electronic structures of hafnium trisulfide (HfS3) and zirconium trisulfide (ZrS3) under varying strains using first-principles calculations combined with the Boltzmann transport equation. Our results reveal that the transverse acoustic phonon mode exhibits parabolic dispersion near the Γ point under tensile strain, consistent with the behavior observed in one-dimensional carbyne chains. For ZrS3, both compressive and tensile strains lead to a reduction in lattice thermal conductivity. In HfS3, thermal conductivity decreases monotonically under compressive strain from 0% to −4%. Thermal conductivity decreases under a 2% tensile strain and increases under a 4% tensile strain. As strain transitions from compressive to tensile, these 1D materials become increasingly anisotropic, with corresponding reductions in bandgaps. These findings offer new insights into strain-engineered thermal and electronic properties, positioning HfS3 and ZrS3 as promising candidates for future applications in electronics and thermoelectrics.