First-principles study of the structure and properties of cationic doping of KDP crystals

Abstract

Potassium dihydrogen phosphate crystal has many advantages, such as higher linear photoelectric coefficient, lower half-wave voltage, wider transmittance band, excellent optical uniformity and the ability to grow into large size crystal, so it is the only nonlinear crystal material that can be used in inertial confinement fusion engineering. However, in practical application, the actual damage threshold of such optical components is far lower than the theoretical damage threshold, and the damage is serious when the ultraviolet laser is irradiated, components.An in-depth study of the characteristics of microdefects and their changes in physical structure and chemical properties under irradiation environment is helpful to understand the mechanism of crystal irradiation damage and improve the damage characteristics of KDP crystal. Considering that different growth processes of KDP crystals lead to different internal defects, the types of defects that determine the damage threshold may also be different. Therefore, this in the present work, based on HSE06 and PBE0 functional, the Sr²⁺，Fe³⁺ at the domestic application of KDP crystal materials, and studies the evolution characteristics of material body defects under high-energy particle irradiation by acquiring the basic characteristics of radiation damage. The research results will provide reference for the development and application of high-power laser devices. First principles calculation method was used to study the defects of Sr²⁺ metal impurity in KDP crystal and its effect on crystal light absorption performance. Considering the influence of electron exchange correlation potential on the crystal structure and the accuracy of electronic properties, the cell parameters and electronic properties of KDP crystal were calculated by using HSE06 and PBE0 functional respectively.