A reflector including a substrate and a plurality of alternating layers of two materials having different indices of refraction disposed on the substrate, wherein the reflector exhibits a central peak in reflectance vs wavelength and the reflectance of the high-energy side-lobes is increased in intensity and the reflectance of the low-energy side-lobes is reduced in intensity and method for making the reflector is disclosed.

A compound-semiconductor photovoltaic cell includes a first photoelectric conversion cell made of a first compound-semiconductor material which lattice matches with GaAs or Ge; a first tunnel junction layer arranged on a deep side farther than the first photoelectric conversion cell in a light incident direction, and including a first p-type (Al.sub.x1Ga.sub.1-x1).sub.y1In.sub.1-y1As (0≤x1<1, 0<y1≤1) layer and a first n-type (Al.sub.x2Ga.sub.1-x2).sub.y2In.sub.1-y2P (0≤x2<1, 0<y2<1) layer; and a second photoelectric conversion cell arranged on a deep side farther than the first tunnel junction layer in the light incident direction, and made of a second compound-semiconductor material which is a GaAs-based semiconductor material. The first photoelectric conversion cell and the second photoelectric conversion cell are joined via the first tunnel junction layer, and a lattice constant of the first n-type (Al.sub.x2Ga.sub.1-x2).sub.y2In.sub.1-y2P layer is greater than a lattice constant of the first photoelectric conversion cell.

A solar cell structure is disclosed that includes a first metal layer, formed over predefined portions of a sun-exposed major surface of a semiconductor structure, that form electrical gridlines of the solar cell; a network of carbon nanotubes formed over the first metal layer; and a second metal layer formed onto the network of carbon nanotubes, wherein the second metal layer infiltrates the network of carbon nanotubes to connect with the first metal layer to form a first metal matrix composite comprising a metal matrix and a carbon nanotube reinforcement, wherein the second metal layer is an electrically conductive layer in which the carbon nanotube reinforcement is embedded in and bonded to the metal matrix, and the first metal matrix composite provides enhanced mechanical support as well as enhanced or equal electrical conductivity for the electrical contacts against applied mechanical stressors to the electrical contacts.

A multijunction solar cell comprising a first solar subcell having a first band gap; a second solar subcell disposed adjacent to said first solar subcell and including an emitter layer, and a base layer having a second band gap less than the first band gap, and being lattice mismatched with the upper first solar subcell, and an intermediate layer directly adjacent to and disposed between first and the second solar subcells and compositionally graded to lattice match the first solar subcell on one side and the second solar subcell on the other side, and arranged so that light can enter and pass through the first solar subcell and at least a portion of which can be reflected back into the first solar subcell by the intermediate layer, and is composed of a plurality of layers of materials with discontinuities in their respective indices of refraction.

A five junction solar cell and its method of manufacture including an upper first solar subcell composed of a semiconductor material having a first band gap; a second solar subcell adjacent to said first solar subcell and composed of a semiconductor material having a second band gap smaller than the first band gap and being lattice matched with the upper first solar subcell; a third solar subcell adjacent to said second solar subcell and composed of a semiconductor material having a third band gap smaller than the second band gap and being lattice matched with the second solar subcell; a fourth solar subcell adjacent to said second solar subcell and composed of a semiconductor material having a fourth band gap smaller than the third band gap and being lattice matched with respect to the third solar subcell; a graded interlayer adjacent to the fourth solar subcell and having a fifth band gap greater than the fourth band gap; and a bottom solar subcell adjacent to the graded interlayer and being lattice mismatched from the fourth solar subcell and having a sixth band gap smaller than the fifth band gap.

An inverted metamorphic multijunction solar cell including an upper first solar subcell, a second solar subcell and a third solar subcell. The upper first solar subcell has a first band gap and positioned for receiving an incoming light beam. The second solar subcell is disposed below and adjacent to, and is lattice matched with, the upper first solar subcell, and has a second band gap smaller than the first band gap. The third solar subcell is disposed below the second solar subcell, and is composed of a GaAs base and emitter layer so as to optimize the efficiency of the solar cell after exposure to radiation. In some implementations, at least one of the solar subcells has a graded band gap throughout its thickness.

A multijunction solar cell in accordance with an example implementation includes a growth substrate; a first solar subcell disposed over or in the growth substrate; a tunnel diode disposed over the first solar subcell; and a grading interlayer directly disposed over the tunnel diode; a sequence of layers of semiconductor material forming a solar cell disposed over the grading interlayer comprising a plurality of solar subcells. The multijunction solar cell also includes a first wafer bowing inhibition layer disposed directly over an uppermost sublayer of the grading interlayer, such bowing inhibition layer having an in-plane lattice constant greater than the in-plane lattice constant of the uppermost sublayer of the grading interlayer. A second wafer bowing inhibition layer is disposed directly over the first wafer bowing inhibition layer.

A multijunction solar cell including an upper first solar subcell; a second solar subcell adjacent to the first solar subcell; a first graded interlayer adjacent to the second solar subcell; a third solar subcell adjacent to the first graded interlayer such that the third subcell is lattice mismatched with respect to the second subcell. A second graded interlayer is provided adjacent to the third solar subcell, and a lower fourth solar subcell is provided adjacent to the second graded interlayer, such that the fourth subcell is lattice mismatched with respect to the third subcell. An encapsulating layer composed of silicon nitride or titanium oxide disposed on the top surface of the solar cell, and an antireflection coating layer disposed over the encapsulating layer.

A solar cell stack includes a first semiconductor solar cell having a p-n junction made of a first material with a first lattice constant, a second semiconductor solar cell having a p-n junction made of a second material with a second lattice constant, and the first lattice constant being at least 0.008 Å smaller than the second lattice constant, and a metamorphic buffer. The metamorphic buffer is formed between the first semiconductor solar cell and the second semiconductor solar cell. The metamorphic buffer includes a series of at least five layers. The lattice constant increases in the series in the direction of the semiconductor solar cell. The lattice constants of the layers of the metamorphic buffer are larger than the first lattice constant. Two layers of the buffer having a doping and the difference in the dopant concentration between the two layers being greater than 4E.sup.17 cm.sup.−3.

A method for producing a multiplicity of semiconductor chips (13) is provided, comprising the following steps: providing a wafer (1) comprising a multiplicity of semiconductor bodies (2), wherein separating lines (9) are arranged between the semiconductor bodies (2), depositing a contact layer (10) on the wafer (1), wherein the material of the contact layer (10) is chosen from the following group: platinum, rhodium, palladium, gold, and the contact layer (10) has a thickness of between 8 nanometres and 250 nanometres, inclusive, applying; the wafer (1) to a film (11), at least partially severing the wafer (1) in the vertical direction along the separating lines (9) or introducing fracture nuclei (12) into the wafer (1) along the separating lines (9), and breaking the wafer (1) along the separating lines (9) or expanding the film (11) such that a spatial separation of the semiconductor chips (13) takes place, wherein the contact layer (10) is also separated. A semiconductor chip, a component and a method for producing the latter are also provided.