Abstract: A monolithically interconnected photovoltaic module having cells which are electrically connected which comprises a substrate, a plurality of cells formed over the substrate, each cell including a primary absorber layer having a light receiving surface and a p-region, formed with a p-type dopant, and an n-region formed with an n-type dopant adjacent the p-region to form a single pn-junction, and a cell isolation diode layer having a p-region, formed with a p-type dopant, and an n-region formed with an n-type dopant adjacent the p-region to form a single pn-junction, the diode layer intervening the substrate and the absorber layer wherein the absorber and diode interfacial regions of a same conductivity type orientation, the diode layer having a reverse-breakdown voltage sufficient to prevent inter-cell shunting, and each cell electrically isolated from adjacent cells with a vertical trench trough the pn-junction of the diode layer, interconnects disposed in the trenches contacting the absorber regions of adja

Abstract: A semiconductor device having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness.

Abstract: A solar cell comprising a substrate of insulating material, a bottom side electrode layer formed on one surface of the substrate, a semiconductor photoelectric conversion layer formed on the bottom side electrode layer, a transparent top side electrode layer formed on the semiconductor photoelectric conversion layer and a non-transparent electrode comprising a plurality of strips of non-transparent conductive layers disposed separately from each other on the top side transparent electrode layer. The solar cell further comprises an additional bottom side electrode layer formed on the opposite surface of the substrate and a plurality of conductive paths connecting the bottom side electrode layer to the additional bottom side electrode layer through holes or slits formed to penetrate the substrate.

Abstract: Thermophotovoltaic (TPV) electric power generators have emitters with infrared (IR) outputs matched with usable wavelengths for converter cells. The emitters have durable substrates, optional refractory isolating layers, conductive refractory metal or inter-metallic emitter layers, and refractory metal oxide antireflection layers. SiC substrates have tungsten or TaSi2 emitter layers and 0.14 micron ZrO2 or Al2O3 antireflection layers used as IR emitters for GaSb converter cells in TPV generators.

Abstract: A radiated energy to electrical energy conversion device and technology is provided where there is a single absorber layer of semiconductor material. The thickness of the absorber layer is much less than had been appreciated as being useful heretofore in the art. Between opposing faces the layer is about 1/2 or less of the carrier diffusion length of the semiconductor material which is about 0.02 to 0.5 micrometers. The thickness of the absorber layer is selected for maximum electrical signal extraction efficiency and may also be selected to accommodate diffusion length damage over time by external radiation.

Abstract: A thermophotovoltaic cell is provided containing strained or lattice-matched quantum wells that have a bandgap smaller than the bandgap of the InGaAs alloy. The alloy is lattice-matched to the substrate. These narrow bandgap quantum wells provide more efficient conversion of IR emission from a black body or other emitter by converting energy from a wider range of wavelengths than a conventional single junction cell. The thickness of the quantum well region and the individual thickness of the individual quantum wells are chosen to avoid lattice mismatch defects which cause degradation of thick conventional lattice mismatched devices.

Abstract: A two-terminal tandem solar cell is provided. The inclusion of thin (few nm-thick) narrow band-gap InGaAs quantum wells in the intrinsic (i) region of the conventional p-i-n GaAs solar cell extends the photo-absorption of the conventional GaInP/GaAs tandem cell toward the infrared. Beginning-of-Life efficiencies in excess of 30% are predicted. Modeling data indicate end-of-life efficiency of these cells will exceed 25% AM0.

Abstract: A photovoltaic element having a specific transparent and electrically conductive layer on a back reflecting layer, said transparent and electrically conductive layer comprising a zinc oxide material and having a light incident side surface region with a cross section having a plurality of arcs arranged while in contacted with each other, said arcs having a radius of curvature in the range of 300 .ANG. to 6 .mu.m and an angle of elevation from the center of the curvature in the range of 30 to 155.degree., and said cross section containing regions comprising said plurality of arcs at a proportion of 80% or more, compared to the entire region of the cross section.

Abstract: Efficient broader spectrum monolithic solar cells are produced by coupling a CIS or CIGS polycrystalline semiconductor to an amorphous silicon semiconductor. Coupling can be accomplished with a n-type conductor, such as cadmium sulfide or microcrystalline n-doped amorphous silicon. Cadmium sulfide can be deposited on the CIS or CIGS polycrystalline semiconductor by solution growth, sputtering or evaporation. A transparent conductive oxide can be deposited on the cadmium sulfide by low pressure chemical vapor deposition. The microcrystalline n-doped amorphous silicon and the amorphous silicon semiconductor can be deposited by enhanced plasma chemical vapor deposition. The amorphous silicon can comprise: hydrogenated amorphous silicon, hydrogenated amorphous silicon carbon, or hydrogenated amorphous silicon germanium. Triple junction solar cells can be produced with an amorphous silicon front cell, an amorphous silicon germanium middle cell, and a CIS or CIGS polycrystalline back cell, on a substrate.

Abstract: The invention relates to a device structure and crystal growth process for making the same, whereby single-crystal semiconductor layers are formed over metal or composite layers. The metal layers function as buried reflectors to enhance the performance of LEDs, solar cells, and photodiodes. The structure may also have application to laser diodes. The structures are made by a modification of a well-established metallic solution growth process. The lateral overgrowth process can be enhanced by imposing an electric current at the growth interface (termed liquid-phase electro-epitaxy). However, the use of an electric current is not crucial. The epitaxial lateral overgrowth technique was also applied to silicon growth on metal-masked silicon substrates.

Abstract: A semiconductor thin film comprises an n-type compound semiconductor layer including at least one element from each of groups Ib, IIIb, VIb and II. A solar cell using this semiconductor thin film comprises a substrate and a rear electrode, a p-type compound semiconductor layer, an n-type compound semiconductor layer, an n-type semiconductor layer, a window layer, and a transparent conductive film, formed in this order on the substrate. The n-type compound semiconductor layer including at least one element from each of groups Ib, IIIb, VIb and II has a high carrier density.

Abstract: Efficient thermophotovoltaic conversion can be performed using photovoltaic devices with a band gap in the 0.75-1.4 electron volt range, and selective infrared emitters chosen from among the rare earth oxides which are thermally stimulated to emit infrared radiation whose energy very largely corresponds to the aforementioned band gap. It is possible to use thermovoltaic devices operating at relatively high temperatures, up to about 300.degree. C., without seriously impairing the efficiency of energy conversion.

Abstract: A TPV cell apparatus with a base region of GaSb crystals. The GaSb crystals are of varying orientations and joined at grain boundaries. A surface region is provided on the GaSb crystals. The GaSb crystals are Tellurium doped N-type GaSb and the surface region is thin Zinc doped P-type GaSb cells. The surface region faces an infrared source. A bus region is connected to a metal grid connected which is in contact with the surface region of the cell. A continuous metal layer is in contact with the GaSb crystals. A multilayer coating is provided on a front side of the cell. The multilayer coating forms an infrared filter for transmitting convertible infrared energy to the cell and for reflecting as much of non-convertible infrared energy back to the IR source as possible. A TPV generator may be provided with the TPV cells.

Abstract: Transparent conductive ZnO films are formed at a high rate, are equal in performance to those formed by MOCVD and have a large area, while the influence of sputtering bombardment is reduced. A method for producing transparent conductive ZnO films is used to produce the window layer of a CIGS thin-film solar cell. A first conductive film functioning as an interface-protective film is formed on a high-resistance-buffer (interfacial) layer by low-output (100 W or lower) RF sputtering using a ZnO target while reducing sputtering bombardment. Second and third conductive films for the window layer are then formed by DC magnetron sputtering in steps using a ZnO--Al target in each step.

Abstract: A dot-junction photovoltaic cell using high absorption semi-conductors increases photovoltaic conversion performance of direct band gap semi-conductors by utilizing dot-junction cell geometry. This geometry is applied to highly absorbing materials, including In.sub.x-1 Ga.sub.x As. The photovoltaic cell configured to be separated into a thin active region and a thick, inactive substrate, which serves as a mechanical support.

Abstract: The photo-semiconducting electrode of the present invention comprises a semiconducting substrate, a chemically adsorbed film formed thereon composed of at least one compound selected from the compounds represented by the formulas: formulas (I) R.sup.1 M.sup.1 Y.sub.1.sub.3, (II) R.sup.1 R.sup.2 M.sup.1 Y.sup.1.sub.2, (III) R.sup.1 R.sup.2 R.sup.3 M.sup.1 Y.sup.1 and (IV) R.sup.1 --SH, respectively, and a dye which is fixed to the surface of the chemically adsorbed film and has a functional group capable of reacting with a halogen atom. Because of this, the photo-semiconductor electrode of the present invention is capable of efficiently absorbing solar light and performing energy conversion and superior in photoelectric conversion efficiency, stability and durability. In addition, it can be easily produced.

Abstract: In order to easily and accurately manufacture a micromachine comprising a member which is made of a single-crystalline material and having a complicated structure, an uppermost layer (1104) of a single-crystalline Si substrate (1102) whose (100) plane is upwardly directed is irradiated with Ne atom currents from a plurality of prescribed directions, so that the crystal orientation of the uppermost layer (1104) is converted to such orientation that the (111) plane is upwardly directed. A masking member (106) is employed as a shielding member to anisotropically etch the substrate (1102) from its bottom surface, thereby forming a V-shaped groove (1112). At this time, the uppermost layer (1104) serves as an etching stopper. Thus, it is possible to easily manufacture a micromachine having a single-crystalline diaphragm having a uniform thickness. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction.

Abstract: A solar cell utilizing a chalcopyrite semiconductor and reducing the density of defects on the junction interface of pn junctions is provided. This solar cell includes a substrate, a back electrode formed on the substrate, a p-type chalcopyrite semiconductor thin film formed on the back electrode, an n-type semiconductor thin film formed so as to constitute a pn junction with the p-type chalcopyrite semiconductor thin film, and a transparent electrode formed on the n-type semiconductor thin film. A material having a higher resistivity than the p-type chalcopyrite semiconductor is formed between the p-type chalcopyrite semiconductor thin film and the n-type semiconductor thin film. A thin film made of this material may be formed by deposition from a solution. For example, CuInS.sub.2 is formed on the surface of a p-type chalcopyrite based semiconductor such as CuInSe.sub.

Abstract: A solar cell comprising a substrate of insulating material, a bottom side electrode layer formed on one surface of the substrate, a semiconductor photoelectric conversion layer formed on the bottom side electrode layer, a transparent top side electrode layer formed on the semiconductor photoelectric conversion layer and a non-transparent electrode comprising a plurality of strips of non-transparent conductive layers disposed separately from each other on the top side transparent electrode layer. The solar sell further comrises an additional bottom side electrode layer formed on the opposite surface of the substrate and a plurality of conductive paths for electrically connecting the bottom the electrode layer to said additional bottom side electrode layer through holes or slits formed to penetrate the substrate. Each of the strips of the non-transparent conductive layers is located just above each of the conductive paths, respectively.

Abstract: This invention relates to a photoelectric transfer device which comprises a photoelectric transfer element, a cholesteric liquid crystal layer and an ultraviolet cut-off layer, said cholesteric liquid crystal layer being arranged between said photoelectric transfer element and said ultraviolet cut-off layer and said ultraviolet cut-off layer being arranged at the side for the incidence of light. According to this invention, there is provided a colorful photoelectric transfer device which is prepared at an inexpensive cost without a marked decrease in the generation efficiency of the photoelectric transfer element and is fit to be used over a prolonged period.

Abstract: A multilayer solar cell with bypass diodes includes a stack of alternating p and n type semiconductor layers 10, 11, 12, 13, 14 arranged to form a plurality of rectifying photovoltaic junctions 15, 16, 17, 18. 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 33, 34 with n-or p-type impurities depending upon the layers to which the respective contact is to be connected and the grooves being filled with metal contact material 31, 32. One or more bypass diodes are provided by increasing the doping levels on either side 10, 13 of one or more portions of the junctions 16 of the cell such that quantum mechanical tunnelling provides a reverse bias characteristic whereby conduction occurs under predetermined reverse bias conditions. Ideally, the doping levels in the bypass diodes is 10.sup.18 atoms/cm.sup.3 or greater and the junction area is small.

Abstract: The stainless steel sheet useful as a substrate for non-single crystalline semiconductor solar cells has minute ripples with undulations along a rolling direction, and its surface roughness is controlled in the range of R.sub.z 0.3-1.4 .mu.m and R.sub.max 0.5-1.7 .mu.m. It is manufactured by finish cold rolling a stainless steel strip with a reduction ratio of at least 20% at a rolling speed of at least 400 m/min. using work rolls polished with abrasives of gage #100-#400 at a final pass, annealing the rolled strip in an open-air atmosphere and then electrolytically pickling the annealed strip in a nitric acid solution. Since minute ripples with undulations are formed on the surface of the stainless steel sheet, an energy conversion efficiency is increased by acceleration of scattering and multiple reflection of incident light rays projected into a non-single crystalline semiconductor layer.

Abstract: A solar cell with a heightened open-circuit voltage and improved junction quality of the interface between an interfacial layer (or buffer layer) and a thin-film light absorbing layer is disclosed. A thin-film solar cell is fabricated on a glass substrate and includes a metallic back electrode, a light absorbing layer, an interfacial layer, a window layer, and an upper electrode. The solar cell is characterized by the light absorbing layer. The light absorbing layer is a thin film of p-type Cu(InGa)Se.sub.2 (CIGS) of the Cu-III-VI.sub.2 chalcopyrite structure and has such a gallium concentration gradient that the gallium concentration gradually (gradationally) increases from the surface thereof to the inside, thereby attaining a heightened open-circuit voltage. The light absorbing layer has on its surface an ultrathin-film surface layer of Cu(InGa)(SeS).sub.2 (CIGSS), which has such a sulfur concentration gradient that the sulfur concentration abruptly decreases from the surface thereof (i.e.

Abstract: A heterostructure thermionic cooler and a method for making thermionic coolers, employing a barrier layer of varying conduction bandedge for n-type material, or varying valence bandedge for p-type material, that is placed between two layers of material. The barrier layer has a high enough barrier for the cold side to only allow "hot" electrons, or electrons of high enough energy, across the barrier. The barrier layer is constructed to have an internal electric field such that the electrons that make it over the initial barrier are assisted in travel to the anode. Once electrons drop to the energy level of the anode, they lose energy to the lattice, thus heating the lattice at the anode. The barrier height of the barrier layer is high enough to prevent the electrons from traveling in the reverse direction.

Abstract: A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical vapor deposition (MOCVD).

Abstract: The present invention is related to a high efficiency indium gallium phosphide NIP solar cell, wherein an intrinsic layer between a emitter layer and base layer can suppress the Zn memory effect and interdiffusion and also a higher doping concentration in n-type AlInP window layer can be attained and the lifetime of minority carriers also increase for improving the conversion efficiency, thus the present invention may be used in the superhigh efficiency tandom cell so as to be used in the space or in earth as an regenerated energy.

Abstract: A two-terminal voltage or current matched solar cell has up to four photovoltaically active junctions which efficiently convert solar radiation into electricity. The solar cell comprises GaInP, GaAs, and GaInAsP, and in the four junction case, GaInAs is used as well. The invention allows the solar spectrum to be converted into electricity more efficiently than previously.

Abstract: A thermophotovoltaic energy conversion device and a method for making the device. The device includes a substrate formed from a bulk single crystal material having a bandgap (E.sub.g) of 0.4 eV<E.sub.g <0.7 eV and an emitter fabricated on the substrate formed from one of a p-type or an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers.

Abstract: A thermophotovoltaic device and a method for making the thermophotovoltaic device. The device includes an n-type semiconductor material substrate having top and bottom surfaces, a tunnel junction formed on the top surface of the substrate, a region of active layers formed on top of the tunnel junction and a back surface reflector (BSR). The tunnel junction includes a layer of heavily doped n-type semiconductor material that is formed on the top surface of the substrate and a layer of heavily doped p-type semiconductor material formed on the n-type layer. An optional pseudomorphic layer can be formed between the n-type and p-type layers. A region of active layers is formed on top of the tunnel junction. This region includes a base layer of p-type semiconductor material and an emitter layer of n-type semiconductor material. An optional front surface window layer can be formed on top of the emitter layer.

Abstract: A solar cell comprising:a first junction part having a first conductivity type first semiconductor film and a second conductivity type second semiconductor film formed on an upper surface of said first semiconductor film; anda second junction part having a first conductivity type third semiconductor film formed on an upper surface of said second semiconductor film and a second conductivity type fourth semiconductor formed on an upper surface of said third semiconductor film,said junction parts arranged from that having a larger forbidden band width along the direction of progress of light through said semiconductor layers,said first, second, third, and fourth semiconductor films being formed of single-crystalline filming;wherein an interlayer conductor prepared from a metal forming ohmic junctions with each of said junction parts and having a thickness capable of transmitting light therethrough is interposed between said first and second junction parts; andwherein said second semiconductor film arranged on on

Abstract: A precursor for manufacturing a semiconductor thin film in which an oxide thin film comprising at least one element as a dopant, selected from a group which consists of Groups IA, IIA, IIB, VA, and VB elements, and Groups IB and IIIA elements which are main components of the semiconductor thin film are deposited on a substrate, or a precursor for manufacturing a semiconductor thin film which is formed by depositing a thin film of oxide comprising the Groups IB and IIIA elements on the substrate wherein the content of at least one of the Groups IB and IIIA elements is varied in the direction of film thickness, and a method for manufacturing a semiconductor thin film comprising the step of heat treating the precursor for manufacturing the semiconductor thin film in an atmosphere containing a Group VIA element.

Abstract: A hydrogen passivated photovoltaic device such as a solar cell comprises a lattice mismatched substrate such as Ge or Si, and a hydrogen passivated heteroepitaxial layer such as InP grown on the substrate. The hydrogen passivated heteroepitaxial III-V photovoltaic device is produced by exposing a sample of a heteroepitaxial III-V material grown on a lattice-mismatched substrate to reactive hydrogen species at elevated temperatures. Reactive hydrogen forms bonds with dangling bonds along dislocations defined in the sample. The electrical activity in the dislocations is passivated as a result of the hydrogenation process.

Abstract: A polysilane composition containing conductor or semiconductor particles useful as a portion of a non-linear optical device.

Abstract: A solar cell formed from a semiconductor having a relative wide band-gap E.sub.b- characterized by a multi-quantum well system incorporated in the depletion region of the cell in which the quantum wells comprise regions of semiconductor with a smaller band gap separated by small amounts of the wider band-gap semiconductor (E.sub.b) so that the effective band-gap for absorption (E.sub.a) is less than E.sub.b.

Abstract: Disclosed herein is a solar cell which is composed basically of a first semiconductor layer of first conductivity type, a second semiconductor layer of second conductivity type, and a third semiconductor layer formed between them. The third semiconductor layer has a band gap narrower than that of the first and second semiconductor layers. The third semiconductor layer also has a pn junction therein. The semiconductor layers are each separated by a buffer layer in which the composition changes gradually across the thickness so that the lattice mismatch between the semiconductor layers is relieved.

Abstract: In an electrical via structure and fabrication method that is particularly suited to coplanar contact solar cells, an initial opening (38,48a,48b,64) through the substrate is coated and substantially closed with a dielectric material (42,52,80). An inner opening (44) is then formed through the dielectric, and the via is provided with a conductive coating (46,54). The dielectric is initially applied in a liquid state and is thereafter cured to a solid. The need for strong chemical etchants to smooth the via opening prior to application of the dielectric and metallization is eliminated, and a polyimide dielectric on a GaAs/Ge solar cell has resulted in a substantial improvement in leakage resistance and cell efficiency.

Abstract: A monolithic, tandem photovoltaic device is provided having an indium gallium arsenide tunnel junction lattice-matched to adjoining subcells and having high peak current densities and low electrical resistance. A method is provided for relatively low-temperature epitaxial growth of a subcell over the tunnel junction at temperatures which leave intact the desirable characteristics of the tunnel junction.

Abstract: A thin-film solar cell includes a thin active layer of high purity material having opposed front and rear surfaces for light-to-electricity conversion, a structure for supporting the thin active layer, and a rear electrode in contact with the rear surface of the active layer. The supporting structure includes a supporting substrate of a low purity material having opposed front and rear surfaces, on the front surface of which the rear surface of the active layer is disposed, and an insulating barrier layer interposed between the front surface of the supporting substrate and the rear surface of the active layer. The barrier layer prevents impurities in the supporting substrate from diffusing into the active layer. Since the supporting substrate comprises a low purity material, the quantity of the expensive high purity material can be reduced by reducing the thickness of the active layer, resulting in low production costs.

Abstract: A photovoltaic (PV) cell with a single pn-junction is disclosed that is capable of functioning as both a current source and a bypass diode. The photovoltaic cell is made of material that has a low bandgap energy, 1.0 eV, or less. One version of the PV cell is formed of a GaSb wafer doped with Te to form an n-region; the Te concentration is between 6 and 10.times.10.sup.17 atoms/cm.sup.3. Multiple PV cells of this invention can be connected in series or in parallel or in tandem in a primary-booster tandem pair to form a circuit without the requirement of protecting the individual cells of the circuit with a separate bypass diode.

Abstract: A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

Abstract: A gallium-arsenide optical power receiver of the type having a pn junction formed over a substrate and buffer layer has a window layer of a first alloy of aluminum gallium arsenide (Al.sub.x Ga.sub.1-x As) and a conductive layer of a second alloy of aluminum gallium arsenide (Al.sub.1-x Ga.sub.x As). Alternatively, the gallium arsenide optical power receiver has a second window layer of the first alloy of aluminum gallium arsenide disposed on the conductive layer, and a cap layer of gallium arsenide disposed on the second window layer. The sheet resistance of the emitter layer is negated by being in parallel with the low sheet resistance of the conductive layer to minimize the thickness and conductivity of the emitter may therefore be optimized solely for energy conversion efficient.

Abstract: A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.

Abstract: A solar cell or photo diode has an n-type semiconductor layer and a p-type semiconductor layer which form a pn-junction at the metallurgical interface of the layers. A thin sheet of undoped semiconductor is located at the interface or the lower doped layer. The sheet has less recombination centers than its adjacent regions and prevents cross-doping of donors and acceptors from the n- and p-side by cross-diffusion to increase the open circuit voltage and fill-factor of the solar cells or photo diode.

Abstract: A photocell (40) includes a photovoltaic or otherwise photosensitive layer structure (44) on which a passivation or window layer (52) of an environmentally sensitive material such as aluminum gallium arsenide (AlGaAs) and an antireflection (AR) coating (54) are formed. An electrically conductive cap layer (60) delineated in a front contact grid configuration sealingly extends through the AR coating (54) to the window layer (52). An ohmic metal contact (64) is evaporated over and seals the cap layer (60) and the contiguous areas of the AR coating (54). The contact grid interface at which the cap layer (60) contacts the window layer (52) is sealed by the AR coating (54) and the contact (64). The photocell (40) is fabricated by forming, delineating and etching the cap layer (60), forming the AR coating (54) and then forming the contact (64) by evaporation of metal.

Abstract: A method and apparatus for forming a thin solar cell having a substantially planar body comprising a first layer which includes at least one photoactive semiconductor layer. This first layer has a frontal light entrance face, a rear face, and side edge face. A second layer comprising an electrically conductive grid-shaped front contact and an anti-reflection layer is located on the frontal light entrance face. A third layer comprising a front cover glass is fastened substantially adjacent the anti-reflection layer and the front grid-shaped contact. A fourth layer, comprising an electrically conductive rear conductive contact, is located on the rear face of the first layer. Spaced apart from the first layer are two electrically interconnection pads. Each pad has a face suitable for an electrical interconnection.

Abstract: A high-efficiency heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer.

Abstract: In a semiconductor device having a metal electrode on a crystalline semiconductor surface, the metal electrode includes first portions electrically and mechanically connected to the surface and second portions mechanically separated from the surface and having configurations that easily deform. These first and second portions are alternatingly arranged on the surface. Accordingly, stress applied to the semiconductor beneath the electrode is reduced and deformation of the semiconductor element due to thermal stress is prevented, thereby preventing deterioration of element characteristics.

Abstract: A photovoltaic cell (20) with a single pn-junction (46) is disclosed that is capable of functioning as both a current source and a bypass diode. The photovoltaic cell is made of material that has a low bandgap energy, 1.0 eV, or less. One version of the photovoltaic cell is formed of a GaSb wafer doped with Te to form an n-region (22); the Te concentration is between 3 and 15.times.10.sup.17 atoms/cm.sup.3. Multiple photovoltaic cells of this invention can be connected in series and placed in parallel across a like number of photovoltaic cells (76) that do not function as tunnel diodes in order to form a power-generating array (70). The photovoltaic cells are arranged in tandem pairs so that the photovoltaic cells (76), which are transparent to the light absorbed by the photovoltaic cells (20), overlie the photovoltaic cells (20).

Abstract: Zinc diffusion procedures applicable for large scale manufacture of GaAs and GaSb cells used in tandem solar cells having a high energy conversion efficiency. The zinc doping and carrier concentration are restricted to be less than about 10.sup.19 /cm.sup.3 to obtain good light generated carrier collection and hence good short circuit currents. The amount of zinc that is available for diffusion during a drive-in heating step is restricted. Confinement of zinc and arsenic vapors during the heating step may be effected by use of a proximity source wafer or by an encapsulant layer. The zinc diffusion of GaSb is obtained by a homogeneous light diffusion that is followed by a patterned heavy diffusion to give low ohmic contact with the grid lines. Texture etching of the GaSb solar cell is also compatible with this diffusion process.

Abstract: A method for fabricating a thermophotovoltaic energy conversion cell including a thin semiconductor wafer substrate (10) having a thickness (.beta.) calculated to decrease the free carrier absorption on a heavily doped substrate; wherein the top surface of the semiconductor wafer substrate is provided with a thermophotovoltaic device (11), a metallized grid (12) and optionally an antireflective (AR) overcoating; and, the bottom surface (10') of the semiconductor wafer substrate (10) is provided with a highly reflecting coating which may comprise a metal coating (14) or a combined dielectric/metal coating (17).