Optimized Photocathode For Spin-Polarized Electron Sources

Photocathode for highly polarized electron emission has been developed, fabricated, and studied. The photocathode is based on short-period strained AlInGaAs/AlGaAs superlattice grown by molecular beam epitaxy. Deformation of AlInGaAs quantum well results in 87 meV energy splitting between heavy hole and light hole minibands. Electron emission from the developed photocathode demonstrates maximal polarization of 92% with quantum efficiency of 0.85% at room temperature. (C) 2008 American Institute of Physics.