| abstract |
The present invention discloses a photocathode structure that may include one or more of Cs2Te, CsKTe, CsI, CsBr, GaAs, GaN, InSb, CsKSb, or metals, the photocathode structure having a protective film on the outer surface. The protective film includes one or more of ruthenium, nickel, platinum, chromium, copper, gold, silver, aluminum, or alloys thereof. The protective film may have a thickness from 1 nm to 10 nm. The photocathode structure can be used in electron beam tools such as scanning electron microscopes. |