Electronic and optical excitations of K-Sb and Na-Sb crystals DOI Creative Commons
Richard Schier, Caterina Cocchi

Physical Review Materials, Journal Year: 2025, Volume and Issue: 9(5)

Published: May 13, 2025

Recent advances in experimental techniques and computational methods have significantly expanded the family of alkali antimonides, a class semiconducting materials used as photocathodes particle accelerators, unveiling new crystal structures stoichiometries with improved stability quantum efficiency. This work investigates electronic optical properties eight Na- K-based antimonide binary crystals 3:1 1:1 alkali-to-antimony ratios, which were predicted to be stable recent high-throughput screening study. Employing density functional theory many-body perturbation theory, we find that all systems exhibit direct band gaps, except for monoclinic Na8Sb8, has nearly degenerate indirect gap. Optical spectra are characterized by near-infrared absorption onsets intense visible excitations. Our analysis highlights significant role electron-hole correlations, particularly compounds, leading exciton binding energies above 100 meV sharper peaks. In-depth inspection contributions excited states provides additional insight into excitonic effects. By shedding light on fundamental crystals, our results relevant design optimization next-generation electron sources accelerators. Published American Physical Society 2025

Language: Английский

Electronic and optical excitations of K-Sb and Na-Sb crystals DOI Creative Commons
Richard Schier, Caterina Cocchi

Physical Review Materials, Journal Year: 2025, Volume and Issue: 9(5)

Published: May 13, 2025

Recent advances in experimental techniques and computational methods have significantly expanded the family of alkali antimonides, a class semiconducting materials used as photocathodes particle accelerators, unveiling new crystal structures stoichiometries with improved stability quantum efficiency. This work investigates electronic optical properties eight Na- K-based antimonide binary crystals 3:1 1:1 alkali-to-antimony ratios, which were predicted to be stable recent high-throughput screening study. Employing density functional theory many-body perturbation theory, we find that all systems exhibit direct band gaps, except for monoclinic Na8Sb8, has nearly degenerate indirect gap. Optical spectra are characterized by near-infrared absorption onsets intense visible excitations. Our analysis highlights significant role electron-hole correlations, particularly compounds, leading exciton binding energies above 100 meV sharper peaks. In-depth inspection contributions excited states provides additional insight into excitonic effects. By shedding light on fundamental crystals, our results relevant design optimization next-generation electron sources accelerators. Published American Physical Society 2025

Language: Английский

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