Structural design and photoelectron emission characteristics of a new Cs2Te photocathode based on surface plasmon polaritons

Surface plasmon polaritons (SPPs) have been introduced into Cu and K2CsSb photocathodes to substantially improve their quantum efficiency, while no similar studies have been reported on Cs2Te photocathode. In this paper, SPPs were introduced into Cs2Te photocathode by means of micro -nano grating structure, which successfully stimulated local enhanced field to improve photon absorption rate and regulate initial distribution of the excited photoelectrons. In order to explore the effect of SPPs on the performance of Cs2Te photocathode, Monte Carlo method was used to simulate the photoemission process of Cs2Te photocathode before and after the introduction of SPPs. The results showed that the quantum efficiency of Cs2Te photocathode with SPPs was improved by 60% while the thermal emittance remained basically unchanged. The results are of great significance for the development of high -brightness electron sources that are required in the field of particle accelerators.