Patent ID: 9406488
Filing Date: 2016-08-02
CPC Classification: H01J

Claim Text:
1. A method of achieving heightened quantum efficiencies and extended photocathode lifetimes, comprising: a. using an electron beam bombardment to activate color centers in a photocathode, wherein said photocathode comprises a substrate layer, a conductive layer, an alkali halide film disposed on said conductive layer or a semiconductor film disposed on said conductive layer, wherein said electron beam bombardment bombards said alkali halide film or said semiconductor film as a pre-treatment, wherein said electron bombardment generates in-gap color center states or intra-band states in said alkali halide film or said semiconductor film to enable photon excitation in a bandgap of said alkali halide film or said semiconductor film, wherein said color centers comprise energy levels within a band gap of said alkali halide film or said semiconductor film of said photocathode, wherein said electron beam is disposed to directly bombard said photocathode with electrons; and b. using photons from a separate light source for pumping electrons in said color centers of said photocathode, wherein said photon excitation in said bandgap of said alkali halide film or said semiconductor film is provided at a different time from said electron bombardment, wherein said pumped electrons improve a quantum efficiency of said photocathode, wherein said pumped electrons improve the lifetime of said photocathode.