Systematic study of polarized electron emission from strained GaAs/GaAsP superlattice photocathodes

摘要

Spin-polarized electron photoemission has been studied for GaAs/GaAs1-xPx strained superlattice cathodes grown by gas-source molecular beam epitaxy. The superlattice structural parameters are systematically varied to optimize the photoemission characteristics. The heavy-hole and light-hole transitions are reproducibly observed in quantum efficiency spectra, enabling direct measurement of the band energies and the energy splitting. Electron-spin polarization as high as 86% with over 1% quantum efficiency has been observed. (C) American Institute of Physics.