Lattice Strain Effect on the Band Offset in Single-Layer MoS2: An Atomic-Bond-Relaxation Approach

Abstract

Two-dimensional molybdenum disulfide (MoS2) attracts a great deal of interest owing to its potential application in the next generation of electronic devices in recent years. However, the physical mechanism on the strain engineering for the band offset in single-layer MoS2 from the atomistic origin is still a challenge. Herein, we propose an analytical model to address the band offset in single-layer MoS2 modulated by the uniaxial tensile strain based on atomic-bond-relaxation consideration. It was found that the bandgap of single-layer MoS2 shows an approximately linearly red shift with a rate of ∼53.4 meV/% strain under uniaxial tensile strain. The underlying mechanism can be attributed to the variation of crystal potential induced by the changes of bond identities such as bond length, strength, and angle. The results were validated by comparing them with the available evidence, suggesting that the proposed model can be an effective method to clarify the modulation mechanism of relevant electronic properties in two-dimensional semiconductor nanostructures.