Photo-electric junction field-effect sensors

Claim 2

A photoelectric device comprising a semiconducting channel of one conductivity type, two spaced electrodes to said channel representing a source and a drain contact, means to provide a depletion layer along at least a portion of said channel, said depletion layer separating said channel from a conducting gate layer, means to illuminate said device by light generating a photocurrent across said depletion layer, said photocurrent changing the width of said channel and the potential distribution along said channel, thereby modifying the currents through said source and drain contacts in response to the special distribution and intensity of said illumination, said channel electrically biased in the blocking direction against said gate in absence of illumination, and said illumination sufficiently strong to forward bias a section of said channel against said gate.

Claim 3

The device of claim 1 whereby minority carriers are injected across said depletion layer along said forward biased channel section, and said injected minority carriers are recombining with majority carriers to provide light emission by injection luminescence.

Claim 4

The device of claim 1, including a sensor for minority carriers located on said channel, said sensor being activated by minority carriers injected along said forward biased channel section.

Claim 5

The device of claim 3 whereby said sensor is a p-n junction collector.

Claim 6

The device of the claim 3 whereby said sensor is a Schottky barrier collector.

Claim 7

The device of claim 3 whereby said sensor is a metal-insulator-semiconductor capacitor.

Claim 8

A photoelectric device comprising a semIconducting channel of one conductivity type, two spaced electrodes to said channel representing a source and a drain contact, means to provide a depletion layer along at least a portion of said channel, said depletion layer separating said channel from a conducting gate layer, means to illuminate said device by light generating a photocurrent across said depletion layer, said photocurrent changing the width of said channel and the potential distribution along said channel, thereby modifying the currents through said source and drain contacts in response to the spatial distribution and intensity of said illumination, said illumination of a sufficient intensity that a potential extremum forms along said channel, said extremum being attractive for minority carriers in said channel.

Claim 9

A photoelectric device comprising a semIconducting channel of one conductivity type, two spaced electrodes to said channel representing a source and a drain contact, means to provide a depletion layer along at least a portion of said channel, said depletion layer separating said channel from a conducting gate layer, means to illuminate said device by light generating a photocurrent across said depletion layer, said photocurrent changing the width of said channel and the potential distribution along said channel, thereby modifying the currents through said source and drain contacts in response to the spatial distribution and intensity of said illumination, said illumination of a sufficient intensity that a potential extremum forms along said channel, said extremum being attractive for minority carriers in said channel.

Claim 10

The device of claim 7 whereby said potential extremum is shifted along said channel by a change in said illumination.

Claim 11

The device of claim 7 whereby said potential extremum is shifted along said channel by a change of potential applied at least to one of said contacts to said channel.

Claim 12

The device of claim 7 whereby said potential extremum is shifted along said channel by combining a change of illumination with a change of potential applied to at least one of said contacts.

Claim 13

The device of claim 7, including means to generate an electric field across said channel in direction normal to said depletion layer, said field of such a polarity as to locate said potential extremum at the boundary of said channel opposite to said depletion layer.

Claim 14

The device of claim 11 whereby said field is built into the channel by a gradient of dopant concentration.

Claim 15

The device of claim 11, including means to populate said potential extremum with minority carriers.

Claim 16

The device of claim 13 whereby said potential extremum is populated with minority carriers at a first position; said potential extremum is then shifted to a second position, thereby transferring at least some of said minority carriers populating said potential extremum to said second position.

Claim 17

The device of claim 13, including an inversion region at said channel boundary, said means to populate comprising minority carriers from said inversion region.

Claim 18

The device of claim 15 whereby said inversion region is induced in a portion of the surface of said semiconducting channel by a potential applied at an electrode spaced from said surface by a solid insulating film.

Claim 19

The device of claim 13 whereby said means to populate comprises a forward biased section of said depletion layer adjacent to said potential extremum, whereby minority carriers are injected into said channel at the position of said potential extremum.

Claim 20

The device of claim 17 whereby the potential of said potential extremum is changed after said population with minority carriers so that the adjacent depletion layer is now reverse biased.

Claim 21

A high impedance semiconducting sensor for the position of a light spot, said sensor comprising (i) a semiconducting channel of length large compared to the light spot and located to expose a section of said sensor along said channel to said light spot; (ii) a depletion layer along said channel which separates said channel from a gate layer; (iii) an electrical contact to each terminal of said channel and another contact to said gate layer; (iv) means to bias at least one of said contacts to a terminal of said channel with respect to said gate layer so that said channel is electrically pinched off at said terminal; whereby the electric current through said terminal becomes independent of said terminal bias, which is commonly known as saturation; (v) the light of said light spot of a sufficiently short wavelength to generate a photocurrent across said depletion layer, thereby affecting said electric current through said terminal; (vi) said light of sufficient intensity so that said saturation current becomes substantially independent of said light intensity, whereby said saturation current becomes indicative of the position of said illumination of said channel and is substantially independent of said light intensity and of said terminal voltage.

Claim 22

A high impedance semiconducting sensor for the position of a light spot, said sensor comprising (i) a semiconducting channel of length large compared to the light spot and located to expose a section of said sensor along said channel to said light spot; (ii) a depletion layer along said channel which separates said channel from a gate layer; (iii) an electrical contact to each terminal of said channel and another contact to said gate layer; (iv) means to bias at least one of said contacts to a terminal of said channel with respect to said gate layer so that said channel is electrically pinched off at said terminal; whereby the electric current through said terminal becomes independent of said terminal bias, which is commonly known as saturation; (v) the light of said light spot of a sufficiently short wavelength to generate a photocurrent across said depletion layer, thereby affecting said electric current through said terminal; (vi) said light of sufficient intensity so that said saturation current becomes substantially independent of said light intensity, whereby said saturation current becomes indicative of the position of said illumination of said channel and is substantially independent of said light intensity and of said terminal voltage.

Claim 23

A semiconducting photoelectric device, comprising a semiconducting channel having a source and a drain terminal; said channel line on one side by a depletion layer which separates said channel from a gate layer; means to bias electrically said terminals against said gate layer; means to illuminate said channel with radiation causing a photoelectric current across said depletion layer, said radiation being sufficiently intense to cause a potential extremum in the channel; means to shift the position of said potential extremum along said channel; another side of said channel lined by a multiplicity of sensors for minority carriers in the channel; said sensors spaced in the direction of said channel from each other; said sensors electrically activated in a selective manner, by said shifting of said potential extremum.

Claim 24

A semiconducting photoelectric device, comprising a semiconducting channel having a source and a drain terminal; said channel line on one side by a depletion layer which separates said channel from a gate layer; means to bias electrically said terminals against said gate layer; means to illuminate said channel with radiation causing a photoelectric current across said depletion layer, said radiation being sufficiently intense to cause a potential extremum in the channel; means to shift the position of said potential extremum along said channel; another side of said channel lined by a multiplicity of sensors for minority carriers in the channel; said sensors spaced in the direction of said channel from each other; said sensors electrically activated in a selective manner, by said shifting of said potential extremum.

Claim 25

The device of claim 20 whereby said selective activation is caused by said potential extremum biasing in the forward direction a section of said depletion layer separating said channel and said gate thereby causing minority carrier injection into said channel, said section located opposite to a selected sensor.

Claim 26

The device of claim 20 whereby said selective activation is caused by minority carriers already contained by said potential extremum when still located at a position spaced from a selected sensor, said minority carriers subsequently moved to the position of said selected sensor by said shift of said potential extremum.

Claim 27

A semiconducting device comprising a semiconducting substrate of one conductivity type hereafter referred to as gate, a thin semiconducting layer of the opposite conductivity type hereafter referred to as channel, said channel overlying said gate and separated from said gate by a p-n junction, source and drain contacts to said channel, means to bias said channel electrically against said gate and means to illuminate said device to generate a potential extremum in said channel between said source and said drain, an insulating layer on the surface of said channel opposite to said gate, contacts on said insulating layer spaced along said channel as to provide a multiplicity of metal-insulator-semiconductor capacitors with said channel, charge transfer of minority carriers among said metal insulator semiconductor capacitors, said charge transfer induced by a shift of said potential extremum in said channel, said shift caused by a change in combination of bias conditions at the terminals of said channel and of illumination.

Claim 28

A semiconducting device comprising a semiconducting substrate of one conductivity type hereafter referred to as gate, a thin semiconducting layer of the opposite conductivity type hereafter referred to as channel, said channel overlying said gate and separated from said gate by a p-n junction, source and drain contacts to said channel, means to bias said channel electrically against said gate and means to illuminate said device to generate a potential extremum in said channel between said source and said drain, an insulating layer on the surface of said channel opposite to said gate, contacts on said insulating layer spaced along said channel as to provide a multiplicity of metal-insulator-semiconductor capacitors with said channel, charge transfer of minority carriers among said metal insulator semiconductor capacitors, said charge transfer induced by a shift of said potential extremum in said channel, said shift caused by a change in combination of bias conditions at the terminals of said channel and of illumination.

Claim 29

The structure of claim 23 whereby said semiconductor channel comprises an epitaxial silicon film of one conductivity type separated from a transparent insulating substrate by an epitaxial silicon film of the opposite conductivity type, said film of the opposite conductivity type being the gate to said channel, at least part of the outer surface of said channel covered with an insulating silicon compound, electrodes on said insulating compound, said illumination impinging on said epitaxial silicon film of the opposite conductivity type through said transparent insulating substrate.

Claim 30

A photoelectric device comprising a semiconducting channel of one conductivity type, two spaced electrodes to said channel representing a source and a drain contact, means to provide a depletion layer along at least a portion of said channel, said depletion layer separating said channel from a conducting gate layer, means to illuminate said device by light generating a photocurrent across said depletion layer, said photocurrent changing the width of said channel and the potential distribution along said channel, thereby modifying the currents through said source and drain contacts in response to the spatial distribution and intensity of said illumination, said means to illuminate comprising a multiplicity of light sources, optical means to focus the light emitted from saiD light sources on said channel so that the light of each light source illuminates a different section of said channel, said different sections spaced in direction of said channel and means to activate said light sources individually, so that the illuminated section can be shifted along the channel.

Claim 31

A photoelectric device comprising a semiconducting channel of one conductivity type, two spaced electrodes to said channel representing a source and a drain contact, means to provide a depletion layer along at least a portion of said channel, said depletion layer separating said channel from a conducting gate layer, means to illuminate said device by light generating a photocurrent across said depletion layer, said photocurrent changing the width of said channel and the potential distribution along said channel, thereby modifying the currents through said source and drain contacts in response to the spatial distribution and intensity of said illumination, said means to illuminate comprising a multiplicity of light sources, optical means to focus the light emitted from saiD light sources on said channel so that the light of each light source illuminates a different section of said channel, said different sections spaced in direction of said channel and means to activate said light sources individually, so that the illuminated section can be shifted along the channel.

Claim 32

An integrated two-dimensional network of photosensitive devices for electric registration of a light spot, said network comprising i. a set of spaced channels of field effect transistors, ii. crossed by a set of spaced sensors for minority carriers in said channels, iii. said spaced channels on a common gate, each channel separated from said gate by a depletion layer, iv. minority carriers injected into one of said channels from said gate upon illumination by said light spot, said minority carriers activating one of said sensors located adjacent to said illumination whereby the photocurrents in said illuminated channel and in said adjacent sensor define the position of said illuminated spot.

Claim 33

An integrated two-dimensional network of photosensitive devices for electric registration of a light spot, said network comprising i. a set of spaced channels of field effect transistors, ii. crossed by a set of spaced sensors for minority carriers in said channels, iii. said spaced channels on a common gate, each channel separated from said gate by a depletion layer, iv. minority carriers injected into one of said channels from said gate upon illumination by said light spot, said minority carriers activating one of said sensors located adjacent to said illumination whereby the photocurrents in said illuminated channel and in said adjacent sensor define the position of said illuminated spot.