Author Correction: Rugged bialkali photocathodes encapsulated with graphene and thin metal film.

The subheading "Photoemission measurement", now reads: "Spectral response photoemission measurements." Finally, in the Methods, under the subheading 'Sandwiching bialkali antimonide photocathodes between graphene and nickel thin films', "Graphene consisting of mainly monolayer regions with some multiple layer regions was synthesized via chemical vapor deposition (CVD) SP 43 sp on Cu substrates and transferred onto TEM mesh grids using an established polymer-supported method that involves distilled water exposure SP 44 sp . [Extracted from the article]