A high-brightness large-diameter graphene coated point cathode field emission electron source.

ABSTRACT: There have been several long-standing problems of cold field emission sources for electron microscopy and lithography that have prevented their widespread use, such as their inherent ultrahigh vacuum condition requirement (<10^-9 torr), relatively poor current stability and rapid emission decay. This paper presents a cold field emission electron source which overcomes these problems based upon using a graphene-coated nickel point cathode. Preliminary experiments demonstrate that it provides stable emission for relatively large tip diameters (micron sizes), can operate in high vacuum conditions (>10^-8 torr) and has an ultralow work function value of 1.10 ± 0.07 eV. It has an estimated reduced brightness value of 1.46 × 10⁹ A m^-2 sr^-1 V

SUBMITTER: Shao X 

PROVIDER: S-EPMC5876327 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature