Title :
Diamond cold cathode
Author :
Geis, M.W. ; Efremow, N.N. ; Woodhouse, J.D. ; McAleese, M.D. ; Marchywka, M. ; Socker, D.G. ; Hochedez, J.F.
Author_Institution :
MIT Lincoln Lab., Lexington, MA, USA
Abstract :
Diamond cold cathodes have been formed by fabricating mesa-etched diodes using carbon ion implantation into p-type diamond substrates. When these diodes are forward biased, current is emitted into vacuum. The cathode efficiency (emitted current divided by diode current) varies from 2*10/sup -4/ to 1*10/sup -10/ and increases with the addition of 10/sup -2/-torr partial pressure of O/sub 2/ into the vacuum system. Current densities of 0.1 to 1 A-cm/sup -2/ are estimated for a diode current of 10 mA. This compares favorably with Si cold cathodes (not coated with Cs), which have efficiencies of approximately 2*10/sup -5/ and current densities of approximately 2*10/sup -2/ A-cm/sup -2/. It is believed that higher current densities and efficiencies can be obtained with more efficient cathode designs and an ultrahigh-vacuum environment.<>
Keywords :
cathodes; cold-cathode tubes; diamond; elemental semiconductors; 10 mA; 1E-2 torr; C crystal cold cathodes; C ion implantation; O/sub 2/ ambient; cathode efficiency; current densities; diamond cold cathodes; diode current; emission into vacuum; mesa-etched diodes; p-type diamond substrates; semiconductors; ultrahigh-vacuum environment; wide bandgap materials; Cathodes; Conducting materials; Current density; Diamond-like carbon; Diodes; Electrons; Elementary particle vacuum; Energy states; Ion implantation; Substrates;
Journal_Title :
Electron Device Letters, IEEE
