Tunable ideal strength of ZrSe₂ monolayer by charge doping

Based on first-principles calculations, we investigated the effect of charge doping on the stability of ZrSe₂ monolayer under external biaxial tensile strain. The phonon dispersions are obtained and show that both electron and hole dopings can suppress the soft phonon modes under tensile strain. With the carrier concentration increasing, the ideal strength of ZrSe₂ monolayer increases significantly at first, and then reaches a maximum value. The maximum ideal strengths of ZrSe₂ under hole and electron dopings are larger than that of neutral monolayer by 79% and 56%, respectively.