title: Carbon nanotube based photocathodes.
abstract: This paper describes a novel photocathode which is an array of vertically aligned multi-walled carbon nanotubes (MWCNTs), each MWCNT being associated with one p-i-n photodiode. Unlike conventional photocathodes, the functions of photon-electron conversion and subsequent electron emission are physically separated. Photon-electron conversion is achieved with p-i-n photodiodes and the electron emission occurs from the MWCNTs. The current modulation is highly efficient as it uses an optically controlled reconfiguration of the electric field at the MWCNT locations. Such devices are compatible with high frequency and very large bandwidth operation and could lead to their application in compact, light and efficient microwave amplifiers for satellite telecommunication. To demonstrate this new photocathode concept, we have fabricated the first carbon nanotube based photocathode using silicon p-i-n photodiodes and MWCNT bunches. Using a green laser, this photocathode delivers 0.5 mA with an internal quantum efficiency of 10% and an I(ON)/I(OFF) ratio of 30.
authors.affiliation: Nanocarb Laboratory, Thales-Ecole Polytechnique, Route Departementale 128, 91767 Palaiseau, France.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Hudanski
authors.forename: Eric
authors.initials: E
authors.lastname: Minoux
authors.forename: Laurent
authors.initials: L
authors.lastname: Gangloff
authors.forename: Kenneth B K
authors.initials: KB
authors.lastname: Teo
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Schnell
authors.forename: Stephane
authors.initials: S
authors.lastname: Xavier
authors.forename: John
authors.initials: J
authors.lastname: Robertson
authors.forename: William I
authors.initials: WI
authors.lastname: Milne
authors.forename: Didier
authors.initials: D
authors.lastname: Pribat
authors.forename: Pierre
authors.initials: P
authors.lastname: Legagneux