Photovoltage Effects in Photoemission from Thin GaAs Layers
A set of thin GaAs p-type negative electron affinity (NEA) photocathodes have been used to measure the yield of photoemitted electrons at high intensity excitation. The active layer thickness is 100 nm and the p-type doping ranges from 5 x 10{sup 18} cm{sup 3} to 5 x 10{sup 19} cm{sup 3} for a set of four samples. The results show that the surface escape probability is a linear function of the NEA energy. The surface photovoltage effect on photoemission is found to diminish to zero at a doping level of 5 x 10{sup 19} cm{sup 3}. The experimental results are shown to be in good agreement with calculations using a charge limit model based on surface photovoltage kinetics that assume a constant electron energy relaxation rate in the band bending region.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research (ER) (US)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 784892
- Report Number(s):
- SLAC-PUB-8753; TRN: AH200131%%604
- Resource Relation:
- Other Information: PBD: 9 Apr 2001
- Country of Publication:
- United States
- Language:
- English
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