Comparison of hydrogen vacancies in KDP and ADP crystals: a combination of density functional theory calculations and experiment

Abstract

KDP and ADP crystals were grown by the rapid growth method, and the origin of the extra optical absorption in both crystals has been explored by theoretical method. The calculation results well explain the experimental phenomenon, and confirm the existence of hydrogen vacancies in both crystals.

Electron paramagnetic resonance spectroscopy and first-principles calculations of Cr3+ doped KDP crystals

“…The defect models with Cr atoms replacing K, P, and H atoms and interstitial positions are constructed. The defect formation energies of defects with charge state q dependent on the Femi level position were defined as: [30][31][32][33][34][35][36][37][38][39][40][41][42][43]…”

“…The defect models with Cr atoms replacing K, P, and H atoms and interstitial positions are constructed. The defect formation energies of defects with charge state q dependent on the Femi level position were defined as: 30–43 where E total ( X q ) and E total (pristine) are the total energies of supercells with and without defects, respectively. n i is the specific number of atoms removed or added to the supercell.…”

Hybrid density functional theory calculations for the electronic and optical properties of Fe3+-doped KDP crystals

“…The defect formation energies of defects with the charge state q dependent on the Fermi level position were defined as: 15 where E f ( X q ), E tot ( X q ) and E tot (pristine) are the defect formation energy of the system, total energy of the defective system, and total energy of the pristine system, respectively; n i , μ i , and q are the number of atoms removed or added from the supercells, chemical potential of the defective element, and number of charges carried by the defect, respectively; E f , E v and Δ V are the positions of the Fermi energy level, valence band maximum (VBM) and difference between the average electrostatic potential of the defect system and pristine KDP, respectively. The chemical potential of H was calculated halving the energy of H 2 , and the value was −3.62 eV.…”

Determination of intrinsic defects of functional KDP crystals with flawed surfaces and their effect on the optical properties

“…23 The electronic structure and optical properties of the Fe-doped crystal were calculated by Liu et al 26 The absorption spectra indicated that the Fe-doped crystal has optical absorption in the long-wave region. Sui et al 27 used this calculation method to further investigate the effect of the charge state and internal microscopic stress of point defects on the stability and optical absorption of the crystal structure. The influence of the existence of different point defects on the optical properties of the crystal was explored, but the direct relationship between point defects and laser damage of crystals has not been revealed yet.…”