Abstract There is disclosed an electro optical device comprising a single body of semi insulating semiconductor material having a semi insulating semiconductivity of approximately 108 ohm-centimeters, preferably gallium arsenide. Gallium arsenide in this conductivity range exhibits a photo conductivity characteristic in which there is a relatively linear variance of resistivity with impinging photons. A PN junction is formed in one portion of the substrate and, responsive to electric signals applied across the junction, emits photons affecting the resistivity of the semi insulating layer. Contact to the photo resistive layer can be connected in a circuit as either a switch or a variable resistor, depending upon the level of signals applied across the PN junction.
A semiconductor device comprising a radiation responsive photo sensitive intrinsic semiconductive body portion, a photo emitting PN junction formed in contact with said body portion thereof, highly doped semiconductor electrode portions integral with said intrinsic semiconductive body at a portion spaced from the PN junction and electrical connections made to said highly doped semiconductor electrode portions.
Claim 2
Dependent Claim
56 words
A semiconductor device comprising a radiation responsive photo sensitive intrinsic semiconductive body portion, a photo emitting PN junction formed in contact with said body portion thereof, highly doped semiconductor electrode portions integral with said intrinsic semiconductive body at a portion spaced from the PN junction and electrical connections made to said highly doped semiconductor electrode portions.
Claim 3
Dependent Claim
27 words
A semiconductor device as set forth in claim 1 wherein said photo sensitive body is a semi-insulating gallium arsenide body having a conductivity of approximately 108 ohm-centimeters.
Claim 4
Dependent Claim
17 words
A semiconductor device as recited in claim 2 wherein said gallium arsenide body is doped with chromium.
Claim 5
Dependent Claim
31 words
A semiconductor device as recited in claim 1 and further including electrodes connected to the PN junction on a side of the body portion opposite to the highly doped semiconductor electrodes.
Claim 6
Dependent Claim
25 words
A semiconductor unit as recited in claim 1 wherein said PN junction is formed in an epitaxial layer on one side of said body portion.