2025/03/12 by Hilde Bellersen, Michele Guerrini, Bellersen, Hilde +3 · 1 citation
Engineering · Materials Science · #Electron and X-Ray Spectroscopy Techniques #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Photocathodes and Microchannel Plates #Plasma Diagnostics and Applications
paper · pdf · doi:10.48550/arxiv.2503.09188
openalex publication_date 2025/03/12 · openalex created_date 2025/10/13 · openalex updated_date 2026/07/28
Cs-based semiconductors like Cs3Sb and Cs2Te are currently used as photocathodes in particle accelerators. Their performance as electron sources critically depends on their interaction with intense laser sources. In this work, we investigate from first principles the time-dependent response of Cs3Sb and Cs2Te to ultrafast pulses of varying intensities, ranging from 1~GW/cm2 to 1~PW/cm2. Nonlinear effects, including high harmonic generation, emerge starting from 100~GW/cm2 in Cs3Sb and 200~GW/cm2 in Cs2Te. Above these intensities, the numbers of absorbed photons and excited electrons saturate due to the depletion of one-photon absorption channels, with renewed increases beyond 1~TW/cm2 for Cs3Sb and 5~TW/cm2 for Cs2Te where multi-photon absorption appears. Finally, the analysis of the occupation density in Cs3Sb reveals the onset of tunnel ionization at intensities above 10~TW/cm2. Our findings provide new insights into the nonlinear optical properties of Cs3Sb and Cs2Te, contributing to the optimization of these materials for the development of next-generation photoinjectors.