Abstract: A multilayer solar cell structure includes a stack of alternating p-type and n-type semiconductor layers arranged to form a plurality of rectifying photovoltaic junctions. Low-cost cells are manufactured from low-quality material which is optimized by employing very high doping levels in thin layers. Typically, the doping levels are greater than 10.sup.17 atoms/cm.sup.3, and the thickness of the layers is related to carrier diffusion length in thickness. Contact is made to underlying layers by way of a buried contact structure comprising grooves extending down through all of the active layers, the walls of each groove being doped with n- or p-type impurities depending upon the layers to which the respective contact is to be connected and the grooves being filled or partly filled with metal contact material.

Abstract: A photo cell and a photo cell array which have high photoelectric conversion efficiency, little leakage current, long life, and high reliability, as well as a electrolytic device that employs the cell and array. The photo cell (1) comprises: a base material (2) consisting of p-type semiconductor; a light receiving section (3) being an integral spherical part of the base material (2) which protrudes outward from the surface of the base (2), and has an n-type semiconductor layer formed on the surface of said spherical part, so that a pn junction interface is formed between the base material (2) and the semiconductor layer; a front surface electrode (4) formed from conductive material in ohmic contact with a portion of the surface of the aforementioned sphere; and a lower or back electrode (5) formed from conductive material on the bottom of the aforementioned base material (2), to provide ohmic contact.

Abstract: A semiconductor device having a spiral electrode pattern and fabrication method thereof. The device includes an undoped semiconductor substrate, a first and a second probing pads formed on the substrate, and a pair of electrode fingers extending spirally toward a concentric center from the respective first and second probing pads and interdigitated with each other. The method includes the steps of, patterning an insulation layer on a semiconductor substrate in a spiral structure, depositing a metal layer on the substrate including the insulation layer but excluding the sides of the insulation layer, and etching the insulation layer using a wet etching technique.

Abstract: The accuracy of an active pixel sensor cell is increased by utilizing a reset diode in lieu of the reset transistor that is conventionally used to reset the voltage on the photodiode of the cell. The reset diode, which is largely unaffected by 1/f noise, consistently resets the photodiode to a substantially constant voltage as opposed to the reset transistor which varies the reset voltage on the photodiode across integration periods due to the effect of 1/f noise. In the present invention, the photodiode is formed by forming a well region of a second conductivity type in a substrate of a first conductivity type. The reset diode is then formed by forming a reset region of the first conductivity type in the well region.

Abstract: The specification describes lightwave systems with remotely powered photoelectric generators. Optical power transmitted through the fiber is incident on a remotely located photodiode array. High power conversion efficiency coupled with a specially designed diode array generates sufficient power to operate electromechanical or electrooptic apparatus in the remote station. Long wavelength photodiodes are serially connected to increase the voltage to practical operating levels. In a communication system, with an optical signal transmitted with the optical power, multiplexers are used for separating the optical power from the optical signal. Also disclosed are optimally designed photodetector arrays in which the photodetector elements are segments of a circular or polygonal circularly symmetric array to increase the fill factor of the array.

Abstract: Optically interactive nanostructural element. The element includes a semiconductor substrate including at least one radiation guide region extending into the substrate. The geometry of the substrate material surrounding the radiation guide region is selected so that it acts as a quantum confinement region for electrons in the substrate material and the radiation guide region acts as a classical waveguide for radiation so that the element absorbs or emits light of a wavelength corresponding to the selected geometry. In a preferred embodiment, the optically interactive nanostructural element includes an array of the radiation guide regions spatially disposed over a surface.

Abstract: A substantial portion of the material at the pn junction (27) of the photodiode (37, 41) having an implanted region extending to a surface thereof is selectively removed (39), leaving a very small junction region (35, 43) with the remainder of the p-type (23) and n-type (25) material of each photodiode being spaced apart or electrically isolated at what was originally the junction. In the ion implanted n-type on p-type approach, the majority of the signal is created in the implanted n-type region while the majority of the noise is generated in the p-type region. By selectively removing p-type material, n-type material or both from the pn junction of the diode or otherwise electrically isolating most of the p-type and n-type regions from each other at the pn junction and thereby minimizing the pn junction area, noise is greatly reduced without affecting the signal response of the photodiode.

Abstract: A semiconductor device includes a semiconductor substrate, and a plurality of semiconductor layers formed on the semiconductor substrate and forming a concave lateral surface, the semiconductor layers including an active layer for either emitting light or receiving light, wherein the concave lateral surface is used as either a light-emitting surface or a light-receiving surface.

Abstract: A photodiode built-in semiconductor device is provided that can prevent internal peripheral circuits from erroneously operating due to incident light entering slantingly, or not perpendicular to a top surface of the semiconductor chip. A semiconductor chip 20 includes a photodiode and its peripheral circuits. The region except for the photodiode is covered with a light shielding film 22 of aluminum metallization. An isolation region (P.sup.+) 23 is arranged at an outermost portion of the chip. A dummy island 24 is formed so as to surround the entire portion of the chip 20. An N.sup.+ -type low resistance region 25 is formed in the surface of the dummy island 24. The dummy photodiode is formed by applying a reverse bias potential across the PN junction defined between the isolation region 23 and the dummy island 24.

Abstract: A solar cell includes a first n.sup.+ type layer formed on the upper surface of a p type silicon substrate, a p type layer formed on the back surface of the substrate and having a dopant impurity concentration higher than that of the substrate, and a second n type layer formed at least on the edge face of the substrate so as to connect the first n type layer and the p type layer. The second n type layer has an impurity concentration lower than that of the first n.sup.+ layer proximate the region in contact with the p type layer.

Abstract: A bipolar avalanche phototransistor has a thin, heavily doped base portion adjacent the collector to improve avalanche characteristics. The structure may have a lateral, as well as vertical, collector, with the thin heavily doped base portion adjoining the surface lateral collector.

Abstract: A light receiving device including a semiconductor substrate of a first conductivity type; a first semiconductor layer of a second conductivity type which is formed on the semiconductor substrate of the first conductivity type; and a semiconductor layer of the first conductivity type which elongates from a surface of the first semiconductor substrate of the second conductivity type to reach a surface of the semiconductor substrate of the first conductivity type, the semiconductor layer splitting the first semiconductor layer of the second conductivity type into a plurality of semiconductor regions of the second conductivity type. The portion of the semiconductor layer of the first conductivity type which overlaps with the semiconductor substrate of the first conductivity type is formed as a semiconductor region of the first conductivity type and has a high-impurity density.

Abstract: According to a first aspect of the invention, a light-emitting and light-sensing diode has a doped region with a depth not exceeding 2 .mu.m, for adequate sensitivity, and an impurity concentration of at least 5.times.10.sup.20 atoms/cm.sup.-3, for adequate emission. According to a second aspect of the invention, a light-emitting and light-sensing diode has a doped region with a deep part and a shallow part, and the area of the shallow part is increased to enhance the sensitivity of the diode. This may be done by providing the doped region with a meandering edge, or with one or more interior islands, or by forming the deep and shallow parts separately.

Abstract: A semiconductor position sensitive detector has an epitaxial layer of a second conductivity type formed on a semiconductor substrate of a first conductivity type. A first diffusion layer of the first conductivity type is formed in said epitaxial layer so as to isolate a rectangular portion of this epitaxial layer from the rest. A second diffusion layer of the first conductivity type is further formed in said rectangular portion of the epitaxial layer, in order to increase the resistance value of the epitaxial layer. In addition, due to the formation of the second diffusion layer, two p-n junctions having photoelectric transfer ability are formed in this device. So, a semiconductor position sensitive detector having excellent photoelectric characteristics can be obtained.

Abstract: A new reach-through APD structure which includes a five-layer, double-drift-region, double-junction device, having a p.sup.+ -p-n-p.sup.- -n.sup.+ structure. The middle three layers of the new APD constitute most of the thickness of the device and are fully depleted when the device is biased to its normal operating voltage. In the present invention, only primary carriers generated in the relatively narrow first drift region are subject to the full avalanche gain, resulting in dark current and noise levels much lower than conventional reach-through APD's. The new structure can be used to fabricate integrated arrays of APD's. These arrays are more durable and easily fabricated than are prior art APD's. Additionally, the new array structure does not require segmentation or isolation of the multiplying regions of the different elements of the array, allowing arrays to be made with little or no dead space between elements.

Abstract: photosensor device (41) having tapered photodiodes (53, 55) that are interdigitated and which is compatible with typical ASIC, CMOS and BiCMOS processes. A left side photodiode array of tapered regions (53) of a first conductivity type is disposed into an epitaxial layer of a second conductivity type. This array of photodiodes is coupled together and further coupled to a first output terminal (43). A fight side photodiode array of tapered regions (55) of said first conductivity type is disposed into the epitaxial layer of the second conductivity type, spaced apart from the left side photodiode by a minimum distance. A second output terminal is coupled to the array of fight side photodiodes (51). An incident light spot (39) is focused onto the sensor. The amount of current generated at the first and second output terminals (43, 51) will be proportional to the area of the left photodiode array and the area of the fight photodiode array which is receiving light.

Abstract: A photo IC having a plurality of photodiodes is disclosed. A semiconductor region to absorb stray carriers is provided between the photodiodes. Stray carriers generated by incidence of light are absorbed by the semiconductor region. As a result, crosstalk between the photodiodes is reduced.

Abstract: A light detecting device of the present invention comprises a third semiconductor layer containing a second conductive impurity which is formed in the upper part of a semiconductor layer containing a first conductive impurity and a fourth semiconductor layer containing the second conductive impurity which is formed in the semiconductor layer around the third semiconductor layer with an interval between the layers.

Abstract: In a photovoltaic device, when an internal electric field in a photoelectric conversion layer becomes non-uniform in the surface direction of the layer for a reason such as the interface between a transparent conductive film and the photoelectric conversion layer being formed in an irregular shape, the internal electric field in the photoelectric conversion layer is made uniform by (1) making the thickness of an intrinsic layer inside the photoelectric conversion layer in portions of the photoelectric conversion layer where the internal electric field becomes weak smaller than that in the other portions, (2) providing regions where conductivity is high and activation energy is low in the photoelectric conversion layer in the said portions, or (3) containing a ferroelectric material in a portion of the intrinsic layer inside the photoelectric conversion layer.

Abstract: Three dimensional deep contact amorphous silicon/microcrystalline silicon (a-Si/.mu.c-Si) solar cells which use deep (high aspect ratio) p and n contacts to create high electric fields within the carrier collection volume material of the cell. The deep contacts are fabricated using repetitive pulsed laser doping so as to create the high aspect p and n contacts. By the provision of the deep contacts which penetrate the electric field deep into the material where the high strength of the field can collect many of the carriers, thereby resulting in a high efficiency solar cell.

Abstract: The invention relates to a combination of monolithically integrated semiconductor arrays each having a number of prefabricated standard elements that can be connected together using one or more metalization layers to form different signal processing units. The standard elements prefabricated on the semiconductor array comprise a number of base cells, a number of capacitors, a number of output transistors and a number of photodiodes arranged in rows and columns. The base cells each contain a number of npn and pnp transistors and a number of resistors. The common arrangement of base cells for signal processing and a photodiode array arranged in rows and columns in addition to the capacitors and output transistors permit low cost manufacture at short notice and in small production quantities of a wide variety of different photodetectors with integrated electronic circuits.

Abstract: A photodiode array is provided which includes a cell comprised of at least a substrate, an insulating film formed on the substrate, a semiconductor layer containing an impurity of first conductivity type and provided on the insulating film, an impurity-diffusion layer of second conductivity type formed in the semiconductor layer and reaching the insulating film, and at least one impurity-diffusion layer of the first conductivity type formed within the impurity-diffusion layer of the second conductivity type and reaching the insulating film, wherein pn junctions are defined between the layers of opposite conductivity types and arranged laterally, and of the pn junctions, any pn junction of a predetermined order are connected to each other in series. By virtue of this arrangement, the area of pn junctions per unit area of a substrate is increased thereby contributing to a reduction in chip size and in production cost.

Abstract: A detector circuit, for example for optical radiation, has a detector diode (20) and an amplifier circuit (30) integrated with the diode in the same silicon wafer for amplification of the diode signal. The diode is designed as a lateral diode. The diode and the amplifier circuit are both produced in a homogeneously weakly doped silicon wafer (1).

Abstract: A solid state image pick-up device has a first pixel for outputting a first color signal and a second pixel for outputting a second color signal different from the first color signal. The first and second pixels have semiconductor junctions between the first semiconductor region and the second semiconductor region, respectively, with different junction capacities from each other.

Abstract: The invention relates to a photovoltaic cell (1) comprising a substrate (2) having a support face (4) having a first electrode (6) thereon and a second electrode (10) spaced from the first electrode (6) by a plurality of layers (14, 16; 14, 24, 16) including at least one layer (14) of a semiconducting material with an active junction (J) interface thereat, said active junction (J) having a developed surface area greater than its projected surface area.

Abstract: A phototransistor is provided with a first resistor that operates as a shunt and a second resistor that operates to protect the device from damage that could be caused by a reverse bias condition. The possible damage results from the creation of a PN junction relationship caused by the doping of N conductivity type material with P.sup.+ conductivity type material in order to form the first resistor. This junction relationship creates a parasitic diode that provides a current path between the emitter and collector terminals of the phototransistor. In order to prevent damage that might occur during a reverse voltage connection, a second resistor is connected between the emitter of transistor Q.sub.1 and the first resistor. The second resistor is in series with the junction relationship resulting from the structure used to form the first resistor and therefore serves to limit the current flowing between the emitter and collector terminals of the transistor under reversed bias conditions.

Abstract: A light-receiving semiconductor device with improved light sensitivity. On a semiconductor substrate of a first conductivity type is formed a plurality of buried layers of a second conductivity type divided by a narrow dividing region. A surface semiconductor layer of the first conductivity type covers the buried layers and the substrate. A connecting semiconductor region of the second conductivity type extends from each of the plurality of the buried layers to the surface of the surface semiconductor layer. An anti-light-reflecting film formed on the surface of the surface semiconductor layer covers a region above the dividing region as well as above the plurality of buried layers. Each of the plurality of buried layers forms a light responsive element with the substrate.

Abstract: A semiconductor photodetector has a channel of conductive material which connects two terminal poles and is defined by potential barrier regions and by space-charge regions that can be reduced by means of incident light. The channel is comprised of a conductive layer parallel to the surface and having laterally narrowing barrier regions extending through the layer.

Abstract: Novel semiconductor devices are monolithically defined with p-type and n-type wide bandgap material formed by impurity induced layer disordering of selected regions of multiple semiconductor layers. The devices are beneficially fabricated by simultaneously forming the n-type and p-type layer disordered regions with sufficiently abrupt transitions from disordered to as-grown material. The novel devices include a heterojunction bipolar transistor monolithically integrated with an edge emitting heterostructure laser or a surface emitting laser, a heterostructure surface emitting laser, a heterostructure surface emitting laser having active distributed feedback, devices containing multiple buried layers which are individually contacted such as p-n junction surface emitting lasers, carrier channeling devices, and "n-i-p-i" or hetero "n-i-p-i" devices, and novel interdigitated structures, such as optical detectors and distributed feedback lasers.

Abstract: A planar photosensitive device, such as an array of APDs, includes a planar block of n type semiconductor material having a plurality of p type wells in the block surrounded by a foundation of n type semiconductor material. Each p type well corresponds to an APD pixel and is disposed so as to respectively adjoin a first surface of the block and such that a respective p-n junction is formed between the p type material in the well and the n type material foundation. Each APD pixel further comprises depletion layer profile modification means such that the peak surface electric field of the p-n junction in each well is substantially less than the bulk electric field of the same p-n junction.

Abstract: An LED array in which the optical output distribution in each light emitting region is as uniform as possible. An n electrode 3 is provided on the under surface of a substrate 2 and a p electrode is provided on the upper surface thereof. A multiplicity of light emitting regions 4 are formed on the upper layer of the substrate 2. Two strip-like conductor portions 6c extending over each light emitting region 4 in ohmic contact are connected to each electrode 6 so that a current is efficiently applied to the conductor portions 6c of each light emitting region 4 and the optical output distribution in each light emitting region 4 is made uniform.

Abstract: A photovoltaic device includes an i-type amorphous silicon thin film and a p-type amorphous silicon thin film arranged on portions of an n-type crystalline silicon substrate, a collecting electrode arranged on the amorphous silicon thin film, and an insulating layer arranged around the portions where the amorphous silicon thin film is formed. Thus, a pin junction is formed only below the collecting electrode.

Abstract: A dielectrically isolated photodiode having an increased p-n junction size with improved photo-carrier collection efficiency. The photodiode comprises a first layer of semiconductor material formed on the bottom and the walls of an isolation region; a second layer of semiconductor material formed on the first layer. The second layer forming a first p-n junction with the first layer and having opposite conductivity type compared to that of the first layer. The photodiode also comprises a third layer of semiconductor material formed on the second layer and electrically coupled to the first layer. The third layer having the same conductivity type as the first layer and forming a second p-n junction with the second layer. During operation, the first p-n junction functions to collect photo-generated carriers that extend to the bottom and walls of the isolation region, thereby increasing the active collecting p-n junction area per isolation region area to improve efficiency of the photodiode.

Abstract: The method and apparatus of this invention facilitate operation of a bar code reader over a wider range of working angle and for a wider range of bar code densities. The invention includes improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.

Abstract: An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium.

Abstract: A semiconductor light-emitting device includes a plurality of semiconductor rods, each of which has a pn junction. The semiconductor rods are formed on a semiconductor substrate such that the plurality of semiconductor rods are arranged at a distance substantially equal to an integer multiple of the wavelength of light emitted from the semiconductor rod. With such devices, various novel optical devices such as a micro-cavity laser of which the threshold current is extremely small and a coherent light-emitting device having no threshold value can be realized.

Abstract: This invention relates to a photodetector including a package having a window disposed in a light incident part, and a light detecting element installed in the package. The light detecting element includes a first region formed of a second conduction-type semiconductor and embedded in a first conduction-type semiconductor layer; a second region formed of second conduction-type semiconductor and embedded so as to be spaced from and to surround the first region; and a conductor layer provided both on at least one part of top surface of the first conduction-type semiconductor layer and on at least one part of top surface of the second region. The first region is surrounded by a second conduction-type second region. On the surface of the semiconductor crystal layer, an electrode is formed on the first region, and a reflection preventing layer is formed on that part of the first region inside the electrode, and a device protecting film is formed on that part of the first region outside the electrode.

Abstract: An IR detector array (10) wherein a metal contact pad (20) makes contact to an underlying radiation detector through one or more thin, electrically conductive stripes (20a). The striped pad contact shape is used in conjunction with a highly absorptive and opaque coating (18) that is interposed between a bottom surface of the contact pad and a top surface of the radiation detector. The highly absorptive coating serves to mask the bottom surface of the metal contact pad from any radiation that would impinge thereon and be reflected. As a result, stray or unabsorbed radiation reaching to a region of the contact pad encounters only the relatively small target presented by the edge of the one or more thin electrically conductive stripes.

Abstract: The output of semiconductor optical sources is monitored by a photo detector including a photodiode having a photosensitivity which is less than the total active area of the device. Conveniently these active areas may be arranged in groups. The electrical output of selected areas or groups of areas or both may be arranged to be enabled or disabled as appropriate to provide the required photo responsivity of the device.

Abstract: A photodetector has a substrate made of a first semiconductor type and having a surface, and a plurality of independent diffusion regions formed in the surface of the substrate and made of a second semiconductor type which is opposite to the first semiconductor type so that a pn junction is formed between the substrate and each diffusion region. Discrete photosensitive areas are formed by each of the diffusion regions and blind areas are formed between adjacent ones of the photosensitive areas when a bias voltage is applied across each pn junction, where each of the photosensitive areas have the same area.

Abstract: An LED array in which the optical output distribution in each light emitting region is as uniform as possible. An n electrode 3 is provided on the under surface of a substrate 2 and a p electrode is provided on the upper surface thereof. A multiplicity of light emitting regions 4 are formed on the upper layer of the substrate 2. Two strip-like conductor portions 6c extending over each light emitting region 4 in ohmic contact are connected to each electrode 6 so that a current is efficiently applied to the conductor portions 6c of each light emitting region 4 and the optical output distribution in each light emitting region 4 is made uniform.

Abstract: An integrated photodiode is formed by providing a silicon substrate with a deep recessed tub in excess of about 20 microns, forming an isolated p-n junction on the peripheral tub surfaces, and selectively epitaxially filling the tub with intrinsic silicon. A desired monolithic integrated circuit is fabricated outside the tub periphery using conventional VLSI techniques. A photodiode electrode structure within the tub periphery can be fabricated at the same time as other monolithic circuit components are formed.

Abstract: A new composition of matter is described comprising a stretch oriented electrically-conducting light-polarizing film. An improved light-electric power converting film uses molecular diodes (diads) in this film composition aligned head-to-tail by light and an electric field. The area of the film is utilized more efficiently by reversing the head-to-tail directions of the diads in adjacent areas. This film is laminated to an electrode structure connected to busbars on a substrate sheet. Current flow through the film is unidirectional between pairs of adjacent electrodes, and is summed on busbars connected to an external load. Two such films arranged orthogonally convert about 72% of the incident light power to electric power. A manufacturing device is disclosed. Critical Ranges of parameters are derived and experimental data presented.

Abstract: A buried P-N junction photodiode is obtained in LinBiCMOS process with junctions formed between N+DUF diffused region and both first P-EPI layer and second P-EPI layer. Contact to N+DUF diffused region is made by a small area deep N+collector diffusion or N well diffusion. This novel buried-junction photodiode can be used for several types of unique photodetector structures including: single photodiode with low surface leakage current, multi-junction photodiodes for incident light spectral distribution information and higher efficiency visible response photodetectors. The disclosed structures are compatible with bipolar and CMOS processes for providing on-chip integration of optical photodetectors with Linear ASIC standard cells and other circuit functions.