Insight into the Stability and Properties of Zn‐Doped KH₂PO₄ Crystal by Hybrid Density Functional Theory

Abstract

Abstract Defects are considered as one of the important factors affecting the quality and laser‐induced damage threshold of potassium dihydrogen phosphate (KH 2 PO 4 , KDP). In this study, hybrid density functional theory is used to investigate how the Zn 2+ ions affect the properties of KDP crystal. Since crystal defects often do not exist singly but combine with each other to form clusters, two charge‐compensated defect clusters, Zn K + （Zn 2+ ion substitutes K + ion）+ V K − （potassium vacancy）and Zn K + + V H − (hydrogen vacancy) are modeled in this work to investigate the stability of them, the defect states induced by these defects and the mechanisms of the structural breakdown. Zn 2+ ions have a slight effect on the electronic property and linear optical absorption of KDP crystal. With the increase of Zn 2+ concentration, more defect pairs are generated, which causes the deformation of more O─H bonds linking to PO 4 and then the crystal structure becomes unstable. The laser‐induced damage resistance of the KDP crystalis affected due to the instability of crystal structure.