Photovoltage effects in photoemission from thin GaAs layers

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 5×1018 to 5×1019 cm−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 photovo...

OXIDE EFFECTS ON PHOTOEMISSION FROM HIGH CURRENT GaAs PHOTOCATHODES*

During four years of on line operation of the SLAC polarized electron gun (PEGGY) and polarized LEED (PLEED) system, we have observed and characterized the failure modes of the GaAs (100) photocathodes (PC’s) used in these systems. Several modes are observed. Gradual decreases in electron polarization and intensity are attributed to the physisorption of CO2 on the PC’s during running at LN2 tem...

Thin Film Photoemission Experiments

CP398, Advanced Accelerator Concepts, edited by S. Chattopadhyay, J. McCullough, and E Dahl AIP Press, New York © 1997 747 Downloaded 18 Aug 2009 to 128.97.92.208. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/proceedings/cpcr.jsp

Electron Spin - Polarization in Photoemission from Thin Al , Gal - , As *

Electronic structure of thin ytterbium layers on W(110): A photoemission study

In the present work we report on high-quality results of angle-resolved photoemission studies of thin Yb layers (1-3 ML thick) on a W(110) substrate. Growth of the thin Yb layers was monitored via permanent measurements of photoemission spectra during Yb deposition. This method allows to monitor the thickness of the deposited Yb with very high accuracy due to strong layer-dependent binding ener...