Nature, Vol.393, No.6684, 431-435, 1998
A new surface electron-emission mechanism in diamond cathodes
An electron-emission mechanism for cold cathodes is described based on the enhancement of electric fields at metal-diamond-vacuum triple junctions. Unlike conventional mechanisms, in which electrons tunnel from a metal or semiconductor directly into vacuum, the electrons here tunnel from a metal into diamond surface states, where they are accelerated to energies sufficient to be ejected into vacuum. Diamond cathodes designed to optimize this mechanism exhibit some of the lowest operational voltages achieved so far.