High electrical frequency infrared detector

Claim 2

A photovoltaic detector, comprising: an electrically insulating substrate of an alkali-halide; an epitaxial layer twelve hundred or less Angstrom units thick of semiconductor material having a first type conductivity, deposited on said substrate; the material selected from the group consisting of: lead chalcogenides, cadmium chalcogenides, or mixtures thereof: two major surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a rectifying contact disposed on an area coplanar with one of said major surfaces when said layer is at about room temperature; a region formed in situ by the induced field of the rectifying contact; the region having a second and opposite type conductivity; and a P-N junction formed by the contiguous surfaces of said region and said layer.

Claim 3

The photovoltaic detector set forth in claim 1, further comprising: said region extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a different one of the major surfaces; and said area being that opposed end surface coplanar with said top surface.

Claim 4

The photovoltaic detector set forth in claim 2, further comprising: the opposed end surfaces being separated by a least distance not greater than nine hundred Angstrom units.

Claim 5

The photovoltaic detector set forth in claim 1, further comprising: a plurality of spaced apart rings of a second and opposite type conductivity disposed into said layer, surrounding and spaced apart from said region; each of said rings extending between and terminating in, the two opposed major surfaces, and having two opposed annular end surfaces, each annular end surface being coextensive with a respective one of the major surfaces; the material of said rings formed in situ by the induced field of rectifying contacts and having a predetermined minority charge carrier diffusion length L r ; and a plurality of P-N junctions each formed by one of the surfaces of one of said rings and the contiguous surface of said layer.

Claim 6

The photovoltaic detector set forth in claim 1 or 2 comprising: said semiconductor material selected from the group consisting of: lead telluride (PbTe), lead selenide (PbSe), lead sulfide (PbS), cadmium sulfide (CdS), cadmium selenide (CdSe), lead cadmium sulfide (PbCdS), lead tin telluride (Pb x Sn 1-x Te), lead tin selenide (Pb y Sn 1-y Se), lead tin sulfide (Pb z Sn 1-z S), or alloys thereof, where: 0≦x≦1, 0.4≦y≦1, and 0.8≦z≦1.

Claim 7

The photovoltaic detector set forth in claim 1 or 2, further comprising: an ohmic contact affixed to, and in an electrically conducting relationship with, said layer at a zone of first type conductivity; one of the rectifying and the ohmic contacts forming a ring spaced apart from, but surrounding, the other contact.

Claim 8

The photovoltaic detector set forth in claim 2, further comprising: an ohmic contact affixed to and in an electrically conducting relationship with, said layer at a zone of first type conductivity; one of the rectifying and the ohmic contacts forming a ring spaced apart from, but surrounding, the other contact; a plurality of detached electrical insulators radiating from said region, each insulator extending between said major opposed surfaces, across the material of said layer having a first type conductivity, and through said ring.

Claim 9

The photodetector set forth in claim 1 or 2 wherein the substrate is a crystalline selected from the group consisting of: barium fluoride, lithium fluoride sodium chloride, potassium chloride, cesium fluoride, cesium chloride, cesium bromide, strontium fluoride or mixtures thereof.

Claim 10

The photodetector set forth in claim 1 or 2 wherein the substrate is crystalline barium fluoride.

Claim 11

A semiconductor device comprising: an electrically insulating crystalline substrate of an alkali-halide; an epitaxial layer not thicker than twelve hundred Angstrom units of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length, disposed on said substrate; the material selected from the group consisting of: lead chalcogenides, cadmium chalcogenides, or mixtures thereof; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a non-ohmic contract affixed to an area coplanar with said top surface when said layer is at about room temperature; a region of second and opposite type conductivity formed in situ in said layer by the induced field of the non-ohmic contact; said region extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a different one of the major surfaces, one of the end surfaces including the area; the region having a minority charge carrier concentration, and a minority charge carrier diffusion length; a P-N junction formed by the contiguous surfaces of said region and said layer.

Claim 12

A semiconductor device comprising: an electrically insulating crystalline substrate of an alkali-halide; an epitaxial layer not thicker than twelve hundred Angstrom units of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length, disposed on said substrate; the material selected from the group consisting of: lead chalcogenides, cadmium chalcogenides, or mixtures thereof; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a non-ohmic contract affixed to an area coplanar with said top surface when said layer is at about room temperature; a region of second and opposite type conductivity formed in situ in said layer by the induced field of the non-ohmic contact; said region extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a different one of the major surfaces, one of the end surfaces including the area; the region having a minority charge carrier concentration, and a minority charge carrier diffusion length; a P-N junction formed by the contiguous surfaces of said region and said layer.

Claim 13

The semiconductor device set forth in claim 10, further comprising: an ohmic contact affixed to said layer at a zone of first type conductivity.

Claim 14

The semiconductor device set forth in claim 10, further comprising: an ohmic contact affixed to said layer at a zone of first type conductivity; one of the ohmic and non-ohmic contacts forming a ring spaced apart from, but surrounding, the other contact.

Claim 15

The semiconductor device set forth in claim 12, further comprising: the ring being radially divided into a plurality of segments with adjacent segments spaced apart by a distance not less than the minority charge carrier diffusion length of the layer.

Claim 16

The semiconductor device set forth in claim 12, further comprising: the ring and the material of the epitaxial layer except for the material underlying the other contact, divided into a plurality of segments by a plurality of electrical insulators extending between said major opposed surfaces and through said ring.

Claim 17

The semiconductor device set forth in claim 10, further comprising: an ohmic contact surrounding, but separated by a distance on the order of the minority charge carrier diffusion length of said epitaxial layer from said non-ohmic contact.

Claim 18

The semiconductor device set forth in claim 10, further comprising: an ohmic contact affixed to said layer at a zone of first type conductivity; the ohmic contact forming a ring spaced apart from, but surrounding the non-ohmic contact.

Claim 19

The semiconductor device set forth in claim 16, further comprising: a plurality of detached electrical insulators radiating from said region, each insulator extending between said major opposed surfaces, across the material of said epitaxial layer having a first type conductivity, and through said ohmic contact; whereby absent said ohmic contact, the material of said epitaxial layer having a first type conductivity adjoining opposite side of any of said electrical insulators is electrically coupled only through said region.

Claim 20

A photovoltaic detector, comprising: an electrically insulating crystalline substrate of an alkali-halide; an epitaxial layer having a thickness not greater than twelve hundred Angstrom units of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; the material selected from the group consisting of: lead chalcogenides, cadmium chalcogenides, or mixtures thereof; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; an ohmic contact affixed to said layer at a zone of the first type conductivity; a plurality of spaced apart rectifying contacts deposed upon a plurality of areas of said top surface when said layer is at about room temperature; the areas being spaced apart from the ohmic contact; a plurality of non-contiguous regions of second and opposite type conductivity disposed into said layer; the regions formed in situ by the induced fields of the rectifying contacts; the regions having a minority charge carrier diffusion length L r ; and a plurality of P-N junctions formed by the contiguous surfaces of said regions and said layer.

Claim 21

A photovoltaic detector, comprising: an electrically insulating crystalline substrate of an alkali-halide; an epitaxial layer having a thickness not greater than twelve hundred Angstrom units of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; the material selected from the group consisting of: lead chalcogenides, cadmium chalcogenides, or mixtures thereof; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; an ohmic contact affixed to said layer at a zone of the first type conductivity; a plurality of spaced apart rectifying contacts deposed upon a plurality of areas of said top surface when said layer is at about room temperature; the areas being spaced apart from the ohmic contact; a plurality of non-contiguous regions of second and opposite type conductivity disposed into said layer; the regions formed in situ by the induced fields of the rectifying contacts; the regions having a minority charge carrier diffusion length L r ; and a plurality of P-N junctions formed by the contiguous surfaces of said regions and said layer.

Claim 22

The photovoltaic detector set forth in claim 18, further comprising: each of said regions separated by a distance on the order of the diffusion length L e .

Claim 23

The photovoltaic detector set forth in claim 18, wherein said plurality of regions comprises: a concentric array, including a central region having a width on the order of twice the diffusion length L r , with adjacent regions separated by a distance on the order of the diffusion length L e .

Claim 24

The photovoltaic detector set forth in claim 20, further comprising: each said region other than said central region having a cross-sectional width on the order of the diffusion length L r .

Claim 25

The photovoltaic detector set forth in claim 20, further comprising: each of said regions extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a different one of the major surfaces.

Claim 26

The photovoltaic detector set forth in claim 20, further comprising: the ohmic contact surrounding, but separated by a distance on the order of the minority charge carrier diffusion length L e , from the outermost of said regions.

Claim 27

The photovoltaic detector set forth in claim 23, further comprising: said ohmic contact and said epitaxial layer except for said central region being radially divided into segments by a plurality of electrical insulators.

Claim 28

The photovoltaic detector set forth in claim 23, further comprising: the ohmic contact being radially divided into a plurality of arcuate segments by a plurality of electrical insulators, adjacent segments spaced apart by a distance not less than the minority charge carrier diffusion length L e .

Claim 29

The photovoltaic detector set forth in claim 22, further comprising: the ohmic contact surrounding, but spaced apart from, the outermost of said regions; a plurality of detached electrical insulators radiating from said central region, each insulator extending between said major opposed surfaces, through the material of said epitaxial layer and through said ohmic contact.

Claim 30

The photovoltaic detector set forth in claim 10 or 18 wherein the substrate is a crystalline selected from the group consisting of: barium fluoride, lithium fluoride sodium chloride, potassium chloride, cesium fluoride, cesium chloride, cesium bromide, strontium fluoride or mixtures thereof.

Claim 31

The photovoltaic detector set forth in claim 10 or 18 wherein the substrate is crystalline barium fluoride.

Claim 32

A photodetector, comprised of: an electrically insulating substrate of an alkali-halide; an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length, deposited on the substrate; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof; the epitaxial layer having a thickness not greater than nine hundred Angstrom units; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a first electrical contact affixed to and in an electrically conducting relationship with, said layer at a zone of the first type conductivity; a rectifying contact disposed upon an area of said top surface when said layer is at room temperature; and the area being apart from the first electrical contact and in an electrically conducting relationship with the second electrical contact.

Claim 33

A photodetector, comprised of: an electrically insulating substrate of an alkali-halide; an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length, deposited on the substrate; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof; the epitaxial layer having a thickness not greater than nine hundred Angstrom units; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a first electrical contact affixed to and in an electrically conducting relationship with, said layer at a zone of the first type conductivity; a rectifying contact disposed upon an area of said top surface when said layer is at room temperature; and the area being apart from the first electrical contact and in an electrically conducting relationship with the second electrical contact.

Claim 34

The photodetector set forth in claim 29 wherein the zone and the area are on the same surface.

Claim 35

The photodetector set forth in claim 29, further comprising: a plurality of detached electrical insulators radiating from said area, each insulator extending between said major opposed surfaces through the material, and through said first electrical contact.

Claim 36

A photodetector, comprised of: an electrically insulating substrate of an alkali-halide; an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length, deposited upon the substrate; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof: the layer having a thickness not in excess of twelve hundred Angstrom units, and having a top surface opposite a substrate-mating surface; an ohmic contact disposed upon a zone of one of the surfaces; a rectifying contact disposed upon an area of one of the surfaces when the layer is at room temperature; and the area being apart from the zone.

Claim 37

A photodetector, comprised of: an electrically insulating substrate of an alkali-halide; an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length, deposited upon the substrate; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof: the layer having a thickness not in excess of twelve hundred Angstrom units, and having a top surface opposite a substrate-mating surface; an ohmic contact disposed upon a zone of one of the surfaces; a rectifying contact disposed upon an area of one of the surfaces when the layer is at room temperature; and the area being apart from the zone.

Claim 38

The photodetector set forth in claim 32 wherein the zone and the area are on the same surface of the layer.

Claim 39

The photodetector set forth in claim 32 further comprising: one of the contacts and the epitaxial layer except for the area, being radially divided into segments by a plurality of electrical insulators.

Claim 40

The photodetector set forth in claim 29 or 32 wherein the substrate is a crystalline selected from the group consisting of: barium fluoride; lithium fluoride; sodium chloride; potassium chloride; cesium fluoride; cesium chloride; cesium bromide; strontium fluoride; or mixtures thereof.

Claim 41

The photodetector set forth in claim 29 or 32 wherein the substrate is crystalline barium fluoride.

Claim 42

A photodetector, comprising: an electrically insulating crystalline substrate; an epitaxial layer of semiconductor material having a predetermined first type conductivity, deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a region of second and opposite type conductivity disposed into said layer; said region extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; the material of said region formed in situ by the diffusion of impurities of said second and opposite type conductivity; the P-N junction formed by the contiguous surfaces of the material of said region and said layer; a first electrical contact affixed to, and in an electrically conducting relationship with, said layer at an area of first type conductivity; a second electrical contact affixed to, and in an electrically conducting relationship with, said region of second type conductivity; and a plurality of detached electrical insulators radiating from said region, each extending between said major opposed surfaces, across the material of said layer having a first type conductivity and through said first electrical contact.

Claim 43

A photodetector, comprising: an electrically insulating crystalline substrate; an epitaxial layer of semiconductor material having a predetermined first type conductivity, deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a region of second and opposite type conductivity disposed into said layer; said region extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; the material of said region formed in situ by the diffusion of impurities of said second and opposite type conductivity; the P-N junction formed by the contiguous surfaces of the material of said region and said layer; a first electrical contact affixed to, and in an electrically conducting relationship with, said layer at an area of first type conductivity; a second electrical contact affixed to, and in an electrically conducting relationship with, said region of second type conductivity; and a plurality of detached electrical insulators radiating from said region, each extending between said major opposed surfaces, across the material of said layer having a first type conductivity and through said first electrical contact.

Claim 44

A photodetector, comprising: an electrically insulating crystalline substrate; an epitaxial layer of semiconductor material having a predetermined first type conductivity, deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a region of second and opposite type conductivity disposed into said layer; said region extending between and terminating in, the two major opposed surfaces, and having two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; the material of said region formed in situ by the diffusion of impurities of said second and opposite type conductivity; a P-N junction formed by the contiguous surfaces of the material of said region and said layer; a first electrical contact affixed to, and in an electrically conducting relationship with, said layer at a point of first type conductivity; a second electrical contact affixed to, and in an electrically conducting relationship with, said region of second type conductivity; said second electrical contact being affixed to that opposed end surface coplanar with said top surface; and a plurality of detached electrical insulators radiating from said region, each extending between said major opposed surfaces, across the material of said layer having a first type conductivity, and through said first electrical contact, adjacent pairs of insulators defining equal arcs.

Claim 45

A photodetector, comprising: an electrically insulating crystalline substrate; an epitaxial layer of semiconductor material having a predetermined first type conductivity, deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a region of second and opposite type conductivity disposed into said layer; said region extending between and terminating in, the two major opposed surfaces, and having two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; the material of said region formed in situ by the diffusion of impurities of said second and opposite type conductivity; a P-N junction formed by the contiguous surfaces of the material of said region and said layer; a first electrical contact affixed to, and in an electrically conducting relationship with, said layer at a point of first type conductivity; a second electrical contact affixed to, and in an electrically conducting relationship with, said region of second type conductivity; said second electrical contact being affixed to that opposed end surface coplanar with said top surface; and a plurality of detached electrical insulators radiating from said region, each extending between said major opposed surfaces, across the material of said layer having a first type conductivity, and through said first electrical contact, adjacent pairs of insulators defining equal arcs.

Claim 46

A photodetector, comprising: an electrically insulating crystalline substrate; an epitaxial layer of semiconductor material having a predetermined first type conductivity, a predetermined minority charge carrier concentration, and a predetermined minority charge carrier diffusion length, deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a region of second and opposite type conductivity disposed into said layer; said region extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; each said end surface having a width not less than twice the minority charge carrier diffusion length of said region; the material of said region formed in situ by the diffusion of impurities of said second and opposite type conductivity, and having a predetermined minority charge carrier concentration and a predetermined minority charge carrier diffusion length; a P-N junction formed by the contiguous surfaces of the material of said region and said layer; a first electrical contact affixed to, and in electrically conducting relationship with, said layer at a zone of first type conductivity; a second electrical contact affixed, to and in an electrically conducting relationship with, said region of second type conductivity; said second electrical contact overlying the area of that opposed end surface coplanar with said top; said first electrical contact surrounding, but separated by a distance on the order of the minority charge carrier diffusion length of said epitaxial layer from, said second electrical contact; a plurality of detached electrical insulators radiating from said region, each extending between said major opposed surfaces, across the material of said epitaxial layer having a first type conductivity, and through said first electrical contact; whereby absent said first conductor, the material of said epitaxial layer having a first type conductivity adjoining opposite sides of any of said electrical insulators is electrically coupled only through said region.

Claim 47

A photodetector, comprising: an electrically insulating crystalline substrate; an epitaxial layer of semiconductor material having a predetermined first type conductivity, a predetermined minority charge carrier concentration, and a predetermined minority charge carrier diffusion length, deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; a region of second and opposite type conductivity disposed into said layer; said region extending between and terminating in, the two opposed major surfaces, and having two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; each said end surface having a width not less than twice the minority charge carrier diffusion length of said region; the material of said region formed in situ by the diffusion of impurities of said second and opposite type conductivity, and having a predetermined minority charge carrier concentration and a predetermined minority charge carrier diffusion length; a P-N junction formed by the contiguous surfaces of the material of said region and said layer; a first electrical contact affixed to, and in electrically conducting relationship with, said layer at a zone of first type conductivity; a second electrical contact affixed, to and in an electrically conducting relationship with, said region of second type conductivity; said second electrical contact overlying the area of that opposed end surface coplanar with said top; said first electrical contact surrounding, but separated by a distance on the order of the minority charge carrier diffusion length of said epitaxial layer from, said second electrical contact; a plurality of detached electrical insulators radiating from said region, each extending between said major opposed surfaces, across the material of said epitaxial layer having a first type conductivity, and through said first electrical contact; whereby absent said first conductor, the material of said epitaxial layer having a first type conductivity adjoining opposite sides of any of said electrical insulators is electrically coupled only through said region.

Claim 48

A photodetector, comprising: an electrically insulating, crystalline substrate; an epitaxial layer of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; at least one region of a second and opposite type conductivity disposed into said layer; each said region extending between and terminating in, the two opposed major surfaces, each end surface being coplanar with a respective one of the major surfaces; said end surfaces on both major surfaces arrayed concentrically and centered upon a central region having a width on the order of twice the diffusion length L r , with adjacent end surfaces separated by a distance on the order of the diffusion length L e ; the material of each said region formed in situ by the diffusion of impurities of said second and opposite type conductivity, and having a predetermined minority charge carrier diffusion length L r ; every boundary between material of said layer having the first type conductivity and a region being a P-N junction; a first electrical contact disposed on one of said major surfaces and surrounding the outermost of the coplanar of said end surfaces at a distance on the order of the minority charge carrier diffusion length L e ; and said first electrical contact and said epitaxial layer except for said central region being radially divided into segments by a plurality of electric insulators.

Claim 49

A photodetector, comprising: an electrically insulating, crystalline substrate; an epitaxial layer of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; at least one region of a second and opposite type conductivity disposed into said layer; each said region extending between and terminating in, the two opposed major surfaces, each end surface being coplanar with a respective one of the major surfaces; said end surfaces on both major surfaces arrayed concentrically and centered upon a central region having a width on the order of twice the diffusion length L r , with adjacent end surfaces separated by a distance on the order of the diffusion length L e ; the material of each said region formed in situ by the diffusion of impurities of said second and opposite type conductivity, and having a predetermined minority charge carrier diffusion length L r ; every boundary between material of said layer having the first type conductivity and a region being a P-N junction; a first electrical contact disposed on one of said major surfaces and surrounding the outermost of the coplanar of said end surfaces at a distance on the order of the minority charge carrier diffusion length L e ; and said first electrical contact and said epitaxial layer except for said central region being radially divided into segments by a plurality of electric insulators.

Claim 50

The photodetector set forth in claim 40 further comprised of the layer having a single and central region.

Claim 51

The photodetector set forth in claim 40 further comprised of the layer having a plurality of regions.

Claim 52

The photodetector set forth in claim 40 further comprised of: the first electrical contact being in ohmic contact with the one of said major surfaces; and a second electrical contact being in rectifying contact with said central region.

Claim 53

The photodetector set forth in claim 40 further comprised of: the first electrical contact being in rectifying contact with the one of said major surfaces; and a second electrical contact being in ohmic contact with said central region.

Claim 54

A photodetector, comprising: an electrically insulating, cyrstalline substrate of an alkali-halide; an epitaxial layer of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; at least one region of a second and opposite type conductivity disposed into said layer; each said region extending between and terminating in two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; said end surfaces on both major surfaces arrayed concentrically and centered upon a central region having a width on the order of twice the diffusion length L r , with adjacent end surfaces separated by a distance on the order of the diffusion length L e ; the material of each said region formed in situ by the diffusion of impurities of said second and opposite type conductivity, and having a minority charge carrier diffusion length L r ; every boundary between material of said layer having the first type conductivity and a region being a P-N junction; a first electrical contact disposed on one of said major surfaces and surrounding the outermost of the coplanar of said end surfaces at a distance on the order of the minority charge carrier diffusion length L e ; and said first electrical contact being radially divided into a plurality of segments overlying equal areas of said top surface.

Claim 55

A photodetector, comprising: an electrically insulating, cyrstalline substrate of an alkali-halide; an epitaxial layer of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; at least one region of a second and opposite type conductivity disposed into said layer; each said region extending between and terminating in two opposed end surfaces, each end surface being coplanar with a respective one of the major surfaces; said end surfaces on both major surfaces arrayed concentrically and centered upon a central region having a width on the order of twice the diffusion length L r , with adjacent end surfaces separated by a distance on the order of the diffusion length L e ; the material of each said region formed in situ by the diffusion of impurities of said second and opposite type conductivity, and having a minority charge carrier diffusion length L r ; every boundary between material of said layer having the first type conductivity and a region being a P-N junction; a first electrical contact disposed on one of said major surfaces and surrounding the outermost of the coplanar of said end surfaces at a distance on the order of the minority charge carrier diffusion length L e ; and said first electrical contact being radially divided into a plurality of segments overlying equal areas of said top surface.

Claim 56

The photodetector set forth in claim 45 further comprised of the layer having a single and central region.

Claim 57

The photodetector set forth in claim 46 further comprised of the layer having a plurality of regions.

Claim 58

The photodetector set forth in claim 47 further comprised of: the first electrical contact being in ohmic contact with the one of said major surfaces; and a second electrical contact being in rectifying contact with said central region.

Claim 59

The photodetector set forth in claim 48 further comprised of: the first electrical contact being in rectifying contact with the one of said major surfaces; and a second electrical contact being in ohmic contact with said central region.

Claim 60

A photodetector, comprising: an electrically insulating, crystalline substrate; an epitaxial layer of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; at least one region of a second and opposite type conductivity disposed into said layer; each said region extending between and terminating in, the two opposed major surfaces, each end surface being coplanar with a respective one of the major surfaces; said end surfaces on both major surfaces arrayed concentrically and centered upon a central region having a width on the order of twice the diffusion length, L r , with adjacent end surfaces separated by a distance on the order of the diffusion length L e ; the material of each said region formed in situ by the diffusion of impurities of said second and opposite type conductivity and having a predetermined minority charge carrier diffusion length L r ; every boundary between material of said layer having the first type conductivity and a region being a P-N junction; a first electrical contact disposed on one of the said major surfaces and surrounding the outermost of the coplanar of said end surfaces at a distance on the order of the minority charge carrier diffusion length L e ; and a plurality of detached electrical insulators radiating from said central region, each insulator extending between said major opposed surfaces through the material of said layer, and through said first electrical contact.

Claim 61

A photodetector, comprising: an electrically insulating, crystalline substrate; an epitaxial layer of semiconductor material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length L e , deposited on said substrate; two major opposed surfaces being, respectively, the top and the substrate-mating surfaces of said layer; at least one region of a second and opposite type conductivity disposed into said layer; each said region extending between and terminating in, the two opposed major surfaces, each end surface being coplanar with a respective one of the major surfaces; said end surfaces on both major surfaces arrayed concentrically and centered upon a central region having a width on the order of twice the diffusion length, L r , with adjacent end surfaces separated by a distance on the order of the diffusion length L e ; the material of each said region formed in situ by the diffusion of impurities of said second and opposite type conductivity and having a predetermined minority charge carrier diffusion length L r ; every boundary between material of said layer having the first type conductivity and a region being a P-N junction; a first electrical contact disposed on one of the said major surfaces and surrounding the outermost of the coplanar of said end surfaces at a distance on the order of the minority charge carrier diffusion length L e ; and a plurality of detached electrical insulators radiating from said central region, each insulator extending between said major opposed surfaces through the material of said layer, and through said first electrical contact.

Claim 62

The photodetector set forth in claim 50 further comprised of the layer having a single and central region.

Claim 63

The photodetector set forth in claim 50 further comprised of the layer having a plurality of regions.

Claim 64

The photodetector set forth in claim 50 further comprised of: the first electrical contact being in ohmic contact with the one of said major surfaces; and a second electrical contact being in rectifying contact with said central region.

Claim 65

The photodetector set forth in claim 50 further comprised of: the first electrical contact being in rectifying contact with the one of said major surfaces; and a second electrical contact being in ohmic contact with said central region.

Claim 66

A photodetector, comprised of: an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixture thereof; two major opposed surfaces being, respectively, the top and the bottom surfaces of said layer; a first electrical contact affixed to and in an electrically conducting relationship with, said layer at a zone of the first type conductivity; a rectifying contact disposed upon an area of said top surface when said layer is at room temperature; and the area being spaced apart from the first electrical contact and in an electrical conducting relationship with the second electrical contact.

Claim 67

A photodetector, comprised of: an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixture thereof; two major opposed surfaces being, respectively, the top and the bottom surfaces of said layer; a first electrical contact affixed to and in an electrically conducting relationship with, said layer at a zone of the first type conductivity; a rectifying contact disposed upon an area of said top surface when said layer is at room temperature; and the area being spaced apart from the first electrical contact and in an electrical conducting relationship with the second electrical contact.

Claim 68

A photodetector, comprised of: an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof: the layer having a thickness not in excess of twelve hundred Angstrom units, and having a top surface opposite a bottom surface; an ohmic contact disposed upon a zone of one of the surfaces; a rectifying contact disposed upon an area of one of the surfaces when the layer is at room temperature; and the area being apart from the zone.

Claim 69

A photodetector, comprised of: an epitaxial layer of material having a first type conductivity, a minority charge carrier concentration, and a minority charge carrier diffusion length; the material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof: the layer having a thickness not in excess of twelve hundred Angstrom units, and having a top surface opposite a bottom surface; an ohmic contact disposed upon a zone of one of the surfaces; a rectifying contact disposed upon an area of one of the surfaces when the layer is at room temperature; and the area being apart from the zone.

Claim 70

A photodetector, comprised of: an epitaxial layer of material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof; an ohmic contact disposed upon a zone on a surface of the layer; a rectifying contact disposed upon an area on a surface of the layer when the layer is at room temperature; and the area being apart from the zone.

Claim 71

A photodetector, comprised of: an epitaxial layer of material selected from the group consisting of: lead chalcogenide alloys, cadmium chalcogenide alloys, or mixtures thereof; an ohmic contact disposed upon a zone on a surface of the layer; a rectifying contact disposed upon an area on a surface of the layer when the layer is at room temperature; and the area being apart from the zone.

Claim 72

The photodetector set forth in claims 55 or 57 wherein the epitaxial layer is not thicker than twelve hundred Angstrom units.

Claim 73

The photodetector set forth in claims 55, 56 or 57 wherein the epitaxial layer is not thicker than nine hundred Angstrom units.

Claim 74

The photodetector set forth in claims 55, 56 or 57 wherein the epitaxial layer is not thicker than five hundred Angstrom units.