Negative electron affinity gallium arsenide photocathode grown by molecular beam epitaxy

The molecular-beam-epitaxial technique has been used to grow a high-quality GaAs negative electron affinity photocathode structure with a p-type beryllium doping concentration of 3×1019 cm−3. The reflection mode photoemission characteristics such as the white light sensitivity, the quantum efficiency, the minority carrier (electron) diffusion length, and the electron surface escape probability measured on such a cathode are described. The growth technique followed, offers a precise control over the layer thickness and doping level.