Hybrid Density Functional Theory Calculations for the Crystal Structure and Electronic Properties of Al3+ Doped KDP Crystals

Autor: Yang Li, Zhenshi Li, Baoan Liu, Xun Sun, Mingxia Xu, Lisong Zhang, Xian Zhao, Guodong Lei
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Crystals, Vol 14, Iss 5, p 410 (2024)
Druh dokumentu: article
ISSN: 2073-4352
DOI: 10.3390/cryst14050410
Popis: Intentionally adding select ions such as Al3+ could be helpful in controlling the crystal habit of KDP crystal for high yield of optics. The study of how Al3+ ions affect crystal quality can provide a basis for selecting an appropriate doping level without negatively affecting the optical properties of crystals. Here, the influence of Al3+ ions on the crystal structure and properties of KDP crystals have been investigated by using first-principles calculations. Theoretical calculations show that Al3+ ions mainly replace K sites in KDP crystals and could complex with intrinsic VH− point defects to form AlK2+ + 2VH− cluster defects. The linear absorption spectra indicate that the presence of Al3+ ions has minimal impact on the linear absorption of KDP crystals, aligning well with the experimental findings. And Al3+ ions could cause a slight shortening of the band gap of KDP crystals. However, these ions could bring significant deformations of O-H bonds. As the concentration of Al3+ ions increase, more O-H bonds linking to PO4 groups are distorted in KDP crystals. As a result, the structural instability could be fast enhanced with increasing the defect concentration. Therefore, high concentrations of Al3+ ions could cause the instability of the crystal structure, which finally affects the laser-induced damage resistance of the KDP crystals. This manuscript contributes to a more comprehensive understanding of the physical mechanisms by which different impurity ions affect the optical properties of KDP crystals.
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