Highly doped surface layer for negative electron affinity devices
AssigneeITT Corporation
InventorRobert J. Field
Life of this patent
Estimating the term…
Abstract
A negative electron affinity device has acceptor dopant concentration increased proximate the emitter face of the III-V semiconductor layer and within the depletion zone effected by an overlying CsO negative electron affinity coating. Methods to accomplish dopant concentration include diffusion, ion implantation and doping during crystal growth.
Claims10
A negative electron affinity device comprises:
- (a) a semiconductor layer doped with an electron acceptor dopant, said semiconductor layer having an emitter face from which electrons are emitted;
- and
- (b) a coating of material to produce or enhance negative electron affinity deposited over said semiconductor layer emitter face, said coating setting up a depletion band in said semiconductor layer, said dopant having an increased concentration proximate said emitter face substantially within said depletion band.
In a photoresponsive negative electron affinity device having a semiconductor layer doped with an electron acceptor dopant, said semiconductor layer having an emitter face from which electrons are emitted, and a negative electron affinity coating applied to said emitter face of said semiconductor layer for setting up a depletion band in said semiconductor layer, the improvement therein comprising:
- a concentration gradient for said dopant, wherein said dopant is more highly concentrated proximate said emitter face substantially within said depletion band such that the photoresponse of said device is increased.
Dependencies are inferred from the claim text.