Speaker
Description
Semiconductor photocathodes are key for the fast development of electron accelerators with high current electron beams and photon detectors, to fulfill these requirements one looks for photocathodes that should have merits like high QE, low thermal emittance, long lifetime,etc. Compared to the traditional sequential deposition, the co-evaporation method is reported to yield better surface roughness, film crystallinity and high quantum efficiency for photocathode materials*. Here we present the effort in upgrading the CeC photocathode deposition system to adapt the co-evaporation growth method, the development of the co-evaporation recipe and the preparation of K-Cs-Sb photocathode using the developed system. QE of about 6.3% at wavelength 532 nm was obtained for co-deposited K2CsSb photocathode, where stoichiometry was determined by the deposition rate of each element. The system upgrade also enables the preparation of GaAs photocathodes activating with Cs-Te. In our study, both CsTe and CsTe/CsO activated GaAs are prepared using the “yo-yo” method. QE of about 3.6% and 5.8% at wavelength 532 nm are obtained respectively. Lifetime measurements are performed and results are reported.
Footnotes
*M. Gaowei et al., PHYSICAL REVIEW ACCELERATORS AND BEAMS 22, 073401 (2019)
Funding Agency
Work supported by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704, DE-SC0013190 with the U.S. Department of Energy. The use of National Synchrotron Light Source II at Brookhaven Nat
| Region represented | North America |
|---|---|
| Paper preparation format | Word |
