Field-assisted semiconductor photoemitters for the 1—2-µm range

Photoemission data and model calculations are presented for a field-assisted semiconductor photoemitter which has achieved reflection-mode quantum efficiencies as high as 8.0 percent at 1.55 µm. The cathodes are p-p heterostructures employing lattice-matched InP-InGaAsP alloys. A thin electron semitransparent Schottky barrier provides the biasing contact for field-assisted electron emission. Parameters for optimal photoemission and sources of dark-current emission are discussed.