Strain-tunable lattice and energy gap in bulk black phosphorus

This study employs an optimized model to investigate the lattice deformation and band structure evolutions induced by the tensile strain along the zigzag direction of bulk black phosphorus (bulk BP) and the physical mechanisms behind it. It has been found that the tensile strain leads to the lattice expansion along the zigzag direction, while contracting along the armchair direction, and the out-of-plane lattice undergoes sequential expansion and contraction. This is also accompanied by an increasing and decreasing of the bulk energy gap and eventually reaching zero. Furthermore, one hopping factor has been proposed to connecting the interlayer spacing and the interlayer interaction, which successfully explains the strain-induced evolutions of the bulk energy gap. This work provides a theoretical reference for the strain-induced band engineering of bulk BP.