ZnS shows increased flow stresses under light illumination. Although such photoplasticity is considered to be related to changes in dislocation-mobility induced by light, explicit profiles of Peierls potentials for individual glide partial dislocations in ZnS have not been revealed. In this study, ${30}^{\circ }$ Shockley-partial dislocations with Zn and S cores were treated by DFT. Specific Peierls potential profiles of the individual partial dislocations were quantitatively calculated, and the relevant Peierls stresses were evaluated. It was found that the reconstructed partial dislocations induced by light illumination have much larger Peierls stresses than those of the pristine unreconstructed partial dislocations. In particular, the calculated large Peierls stresses of the reconstructed partial dislocations indicate that these dislocations are indeed immobile under light illumination. These results indicate that atomic reconstruction of the partial-dislocation cores caused by photoexcited carriers is a critical factor contributing to the very low dislocation mobility for experimentally observed photoplasticity in ZnS.

Close

PrevNext

View figure in article

• Defects
• Embrittlement
• Plasticity
• First-principles calculations