Abstract: A process for growing single crystal epitaxial BaF.sub.2 layers on gallium rsenide substrates by slowly reacting Ba, BaCl.sub.2, Bal.sub.2, BaBr.sub.2, BaF.sub.2 .cndot.BaCl.sub.2, BaF.sub.2 .cndot.BaBr.sub.2, BaF.sub.2 .cndot.BaI.sub.2, BaCl.sub.2 .cndot.BaBr.sub.2, Ba.sub.3 (GaF.sub.6).sub.2, BAH.sub.2, or BaO.sub.2 vapor with a clean, hot GaAs substrate at 500.degree. C. to 700.degree. C. in high vacuum until a uniform, thin (.about.12 .ANG.) layer of reaction product is formed and then vapor depositing BaF.sub.2 onto the reaction layer at room temperature to 400.degree. C. to form the single crystal, epitaxial BaF.sub.2 layer.

Abstract: Photoconductive semiconductor material is injected into narrow and closely paced cylindrical channels in an insulating matrix plate to form pixel elements of a high resolution photodetector array. A transparent conductive layer is deposited on one surface of the photoconductor array while light reflecting pads are formed on the elements at the opposite surface. Subsequently, a layer of light modulating material and a transparent conductive layer are deposited on the opposite surface to obtain a high resolution spatial light modulator.

Abstract: Photoconductive semiconductor material is injected into narrow and closely paced cylindrical channels in an insulating matrix plate to form pixel elements of a high resolution photodetector array. A transparent conductive layer is deposited on one surface of the photoconductor array while light reflecting pads are formed on the elements at the opposite surface. Subsequently, a layer of light modulating material and a transparent conductive layer are deposited on the opposite surface to obtain a high resolution spatial light modulator.

Abstract: The semiconductor materials of junction forming layers of a heterojunction tructure are interfaced by a gap region that is graded by degree of alloying of those components of an interfacing material which are respectively compounded in the semiconductor materials of the junction forming layers having different bandgaps and band edges that are aligned by the grading of the interfacing gap region to selectively control rectifying junction characteristics.

Abstract: Radiation absorbing layers of epitaxially grown, photovoltaic materials are eposited in stacked relation on a substrate in alignment with a coincident axis of input radiation impinging on a common optically active surface area of a detector device formed by the stacked layers. Semi-insulating layers space the radiation absorbing layers to electrically separate the signal outputs respectively produced in response to impinging radiation limited to separate and distinct wavelengths within a common spectral range as a result of the interrelationships between bandgap energy properties of the layer materials.

Abstract: An infrared radiation detector having a first semiconductor layer deposited n a substrate to form a diode junction with an overlay contact, is rendered more effective to detect long wavelength radiation by deposit of a second semiconductor layer between the first layer and the overlay contact in a heterojunction arrangement. The semiconductor materials are selected so as to separate radiation absorbing and electrical functions respectively performed within the two layers and to produce an enhanced output across the diode junction between the first layer and the overlay contact.

Abstract: An infrared radiation detector having a first semiconductor layer deposited n a substrate to form a diode junction with an overlay contact, is rendered more effective to detect long wavelength radiation by deposit of a second semiconductor layer between the first layer and the overlay contact in a heterojunction arrangement. The semiconductor materials are selected so as to separate radiation absorbing and electrical functions respectively performed within the two layers and to produce an enhanced output across the diode junction between the first layer and the overlay contact.

Abstract: A single element infrared detector consisting of multiple layers of succeve epilayers of lead chalcogenides or their alloys with tin or cadmium to form two or more adjacent contiguous surfaces whereupon each surface is deposited with an ohmic contact. The multiple adjacent semiconductor surfaces are also each fitted or equipped with an non-ohmic contact that yields novel applications in terms of broad band and narrow scanning, particular when the epilayers are geometrically arranged to selectively allow the transmission of radiation to yield both broad band and narrow band responses concurrently so as to obtain a separate electrical signal from each adjacent contiguous semiconducting epilayer surface.

Abstract: An infrared image detector array is constructed by depositing a plurality non-contiguous strips of infrared radiation responsive, semiconductor material on one side of a base substrate. A contiguous metal semiconductor contact in then overlaid on the plurality of strips thereby forming an individual Schottky barrier detector element wherever the metal contact crosses one of the plurality of strips.

Abstract: In a process for preparing an infrared sentitive photodiode comprising the teps of:(1) forming by vacuum deposition an epitaxial layer of a semiconductor alloy material selected from the group consisting of PbSe, PbTe, PbSe.sub.x Te.sub.1-x, Pb.sub.y Sn.sub.1-y Se, Pb.sub.y Sn.sub.1-y Te, Pb.sub.y Sn.sub.1-y Se.sub.x Te.sub.1-x, Pb.sub.z Cd.sub.1-z Se, Pb.sub.z Cd.sub.1-z Te, and Pb.sub.z Cd.sub.1-z Se.sub.x Te.sub.1-x, wherein 0<x<1, 0<y<1, and 0<z<1, to cover at least a portion of the surface of a substrate composed of an infrared transparent single crystal material selected from the group consisting of(a) alkali metal halides and(b) alkaline earth halides;(2) coating the epitaxial layer of semiconductor alloy material with a thin layer of a lead halide selected from the group consisting of PbCl.sub.2, PbBr.sub.2, PbF.sub.

Abstract: In a process for preparing an infrared sentitive photodiode comprising the teps of:(1) forming by vacuum deposition an epitaxial layer of a semiconductor alloy material selected from the group consissting of PbSe, PbTe, PbSe.sub.x Te.sub.1-x, Pb.sub.y Sn.sub.1-y Se, Pb.sub.y Sn.sub.1-y Te, Pb.sub.y Sn.sub.1-y Se.sub.x Te.sub.1-x, Pb.sub.z Cd.sub.1-z Se, Pb.sub.z Cd.sub.1-z Te, and Pb.sub.z Cd.sub.1-x Se.sub.x Te.sub.1-x, wherein 0<x<1, 0<y<1, and 0<z-1, to cover at least a portion of the surface of a substrate composed of an infrared transparent single crystal material selected from the group consisting of(a) alkali metal halides and(b) alkaline earth halides;(2) coating the epitaxial layer of semiconductor alloy material with a thin layer of a lead halide selected from the group consisting of PbCl.sub.2, PbBr.sub.2, PbF.sub.

Abstract: In a process of preparing an infrared sensitive photodiode comprising the eps of(1) forming by vacuum deposition an epitaxial layer of a semiconductor alloy material selected from the group consisting of PbS, PbSe, PbTe, PbS.sub.x Se.sub.1-x, PbS.sub.x Te.sub.1-x, PbSe.sub.x Te.sub.1-x, Pb.sub.y Sn.sub.1-y S, Pb.sub.y Sn.sub.1-y Se, Pb.sub.y Sn.sub.1-y Te, Pb.sub.y Sn.sub.1-y S.sub.x, Pb.sub.y Sn.sub.1-y S.sub.x Te.sub.1-x, Pb.sub.y Sn.sub.1-y Se.sub.x Te.sub.1-x, Pb.sub.z Cd.sub.1-z S, Pb.sub.z Cd.sub.1-z Se, Pb.sub.z Cd.sub.1-z Te, Pb.sub.z Cd.sub.1-z S.sub.x Se.sub.1-x, Pb.sub.z Cd.sub.1-z S.sub.x Te.sub.1-x, and Pb.sub.z Cd.sub.1-z Se.sub.x Te.sub.

Abstract: A process for preparing an infrared sensitive photodiode comprising the ss of(1) forming by vacuum deposition an epitaxial layer of a semiconductor alloy material which is PbS, PbSe, PbTe, PbS.sub.x Se.sub.1-x, PbS.sub.x Te.sub.1-x, PbSe.sub.x Te.sub.1-x, Pb.sub.y Sn.sub.1-y S, Pb.sub.y Sn.sub.1-y Se, Pb.sub.y Sn.sub.1-y Te, Pb.sub.y Sn.sub.1-y S.sub.x Se.sub.1-x, Pb.sub.y Sn.sub.1-y S.sub.x Te.sub.1-x, Pb.sub.y Sn.sub.1-y Se.sub.x Te.sub.1-x, Pb.sub.z Cd.sub.1-z S, Pb.sub.z Cd.sub.1-z Se, Pb.sub.z Cd.sub.1-z Te, Pb.sub.z Cd.sub.1-z S.sub.x Se.sub.1-x, Pb.sub.z Cd.sub.1-z S.sub.x Te.sub.1-x, or Pb.sub.z Cd.sub.1-z Se.sub.x Te.sub.1-x, wherein 0<x<1, 0<y<1, and 0<z<1, to cover at least a portion of the surface of a substrate composed of an infrared transparent single crystal material which is an alkali halide or an alkaline earth halide;(2) forming a layer of a lead halide which is PbCl.sub.2, PbBr.sub.2, PbF.sub.