Abstract: A method of forming a multijunction solar cell that includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another adjacent solar subcell.

Abstract: A multijunction solar cell includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another solar subcell.

Abstract: An inverted metamorphic multijunction solar cell comprising: an upper first solar subcell having a first band gap; a middle second solar subcell disposed adjacent to the upper first solar subcell and having a second band gap smaller than said first band gap; a graded interlayer disposed adjacent to the middle second solar subcell and having a band gap that remains constant throughout its thickness; a lower third solar subcell disposed adjacent to said graded interlayer and having a fourth band gap that is smaller than said second band gap such that said third solar subcell is lattice mismatched with respect to said second solar subcell; a back surface field (BSF) layer disposed directly adjacent to the base layer of said lower third solar subcell; at least one distributed Bragg reflector (DBR) layer disposed directly adjacent to the back surface field (BSF) layer.

Abstract: A method of forming a multijunction solar cell that includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another adjacent solar subcell.

Abstract: A multijunction solar cell including a substrate and at least one solar subcell having an emitter layer, a base layer, and a window layer adjacent to the emitter layer composed of a semiconductor window material, wherein the window material has a graded composition such that the material at the interface between the top surface of the emitter layer of the at least one solar subcell and the bottom surface of the window layer has a compression as measured by a delta in the Bragg angle from the substrate in a range of 0 to 500 arcseconds in compression, and material at the top surface of the window layer has a tension as measured by a delta in the Bragg angle from the substrate in a range of 50 to 700 arcseconds in tension, wherein the delta in the Bragg angle is obtained from a rocking curve from a triple axis coupled scan of ? and 2? (omega-2theta) using 1.5406 ? radiation.

Abstract: A solar cell comprising an epitaxial sequence of layers of semiconductor material forming a solar cell deposited using an MOCVD reactor; a metal layer disposed on top of the sequence of layers of semiconductor material, the metal layer including a top surface layer composed of gold or silver; a polymer film; depositing a first metallic adhesion layer disposed on the polymer film that has a coefficient of thermal expansion substantially different from that of the top surface layer on one surface of the polymer film; a second metallic adhesion layer deposited over the first metallic adhesion layer and having a different composition from the first metallic adhesion layer and having no chemical elements in common; and the second metallic adhesion layer of the polymer film being permanently bonded to the metal layer of the sequence of layers of semiconductor material by a thermocompressive diffusion bonding technique.

Abstract: The present disclosure provides a multijunction solar cell comprising: an upper solar subcell having an indirect band gap semiconductor emitter layer composed of greater than 0.7 but less than 1.0 mole fraction aluminum and a base layer, the emitter layer and the base layer forming a heterojunction solar subcell; and a lower solar subcell disposed beneath the upper solar subcell, wherein the lower solar subcell has an emitter layer and a base layer forming a photoelectric junction. In some embodiments, the emitter layer of the upper solar subcell is an n-type AlxGa1-xAs layer with 0.7<x<1.0 and having a band gap of greater than 1.85 eV.

Abstract: A multijunction solar cell comprising at least a first subcell and a second subcell, a first alpha layer disposed over said first solar subcell grown using a surfactant and dopant including selenium or tellurium, the first alpha layer configured to prevent threading dislocations from propagating; a metamorphic grading interlayer disposed over and directly adjacent to said first alpha layer; a second alpha layer grown using a surfactant and dopant including selenium or tellurium over and disposed directly adjacent to said grading interlayer to prevent threading dislocations from propagating; wherein the second solar subcell is disposed over said grading interlayer such that the second solar subcell is lattice mismatched with respect to the first solar subcell.

Abstract: A method of forming a multijunction solar cell comprising at least a first subcell and a second subcell, the method including forming a first alpha layer over said first solar subcell using a surfactant and dopant including selenium or tellurium, the first alpha layer configured to prevent threading dislocations from propagating; forming a metamorphic grading interlayer over and directly adjacent to said first alpha layer; forming a second alpha layer using a surfactant and dopant including selenium or tellurium over and directly adjacent to said grading interlayer to prevent threading dislocations from propagating; and forming the second solar subcell over said grading interlayer such that the second solar subcell is lattice mismatched with respect to the first solar subcell.

Abstract: A method of forming a multijunction solar cell comprising an upper subcell, a middle subcell, and a lower subcell comprising providing first substrate for the epitaxial growth of semiconductor material; forming a first solar subcell on said substrate having a first band gap; forming a second solar subcell over said first subcell having a second band gap smaller than said first band gap; and forming a grading interlayer over said second sub cell having a third band gap larger than said second band gap forming a third solar subcell having a fourth band gap smaller than said second band gap such that said third subcell is lattice mis-matched with respect to said second subcell.

Abstract: A multijunction solar cell includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another solar subcell.

Abstract: A method of manufacturing an inverted metamorphic multijunction solar cell is disclosed herein. The method includes forming a lattice constant transition material positioned between a first subcell and a second subcell using a metal organic chemical vapor deposition (MOCVD) reactor. The solar cell further includes at least one distributed Bragg reflector (DBR) layer directly adjacent a back surface field (BSF) layer.

Abstract: A multijunction solar cell includes an upper first solar subcell having a first band gap, a second solar subcell having a second band gap smaller than the first band gap, and a first graded interlayer composed of (InxGa1-x)yAl1-yAs adjacent to the second solar subcell. The first graded interlayer has a third band gap greater than the second band gap subject to the constraints of having the in-plane lattice parameter greater or equal to that of the second subcell and less than or equal to that of the third subcell, wherein 0<x<1 and 0<y<1, and x and y are selected such that the band gap of the first graded interlayer remains constant throughout its thickness at 1.5 eV. A third solar subcell is adjacent to the first graded interlayer and has a fourth band gap smaller than the second band gap such that the third subcell is lattice mismatched with respect to the second subcell.

Abstract: The disclosure describes multi-junction solar cell structures that include two or more graded interlayers.

Abstract: A multijunction solar cell includes an upper first solar subcell, a second solar subcell adjacent to the first solar subcell, a third solar subcell adjacent to the second solar subcell, and a graded interlayer adjacent to the third solar subcell. The graded interlayer has a band gap that is greater than the band gap of the third solar subcell and is composed of a compositionally step-graded series of (InxGa1-x)yAl1-yAs layers with monotonically changing lattice constant, with x and y having respective values such that the band gap of the graded interlayer remains constant throughout its thickness, and wherein 0<x<1 and 0<y<1. A fourth solar subcell is adjacent to the graded interlayer and is lattice mismatched with respect to the third solar subcell. The graded interlayer provides a transition in lattice constant from the third solar subcell to the fourth solar subcell. A lower fifth solar subcell is adjacent to the fourth solar subcell.

Abstract: The present disclosure provides a multijunction solar cell comprising: an upper solar subcell having an indirect band gap semiconductor emitter layer composed of greater than 0.8 but less than 1.0 mole fraction aluminum and a base layer, the emitter layer and the base layer forming a heterojunction solar subcell; and a lower solar subcell disposed beneath the upper solar subcell, wherein the lower solar subcell has an emitter layer and a base layer forming a photoelectric junction. In some embodiments, the emitter layer of the upper solar subcell is an n-type AlxGa1-xAs layer with 0.8<x<1.0 and having a band gap of greater than 2.0 eV.

Abstract: A method of manufacturing a solar cell comprising providing a first semiconductor substrate with an epitaxial sequence of layers of semiconductor material forming a solar cell deposited over the first semiconductor substrate using an MOCVD reactor; depositing a metal layer on top of the sequence of layers of semiconductor material, the metal layer including a top surface layer composed of gold or silver; providing a polymer film; depositing a first metallic adhesion layer that has a coefficient of thermal expansion substantially different from that of the top surface layer on one surface of the polymer film; depositing a second metal adhesion layer over the first metallic adhesion layer and having a different composition from the first layer and having no chemical elements in common; and adjoining the second adhesion layer of the polymer film to the metal layer of the sequence of layers and permanently bonding it thereto by a thermocompressive diffusion bonding technique.

Abstract: The present disclosure provides a multijunction solar cell that includes: a first sequence of layers of semiconductor material forming a first set of one or more solar subcells; a graded interlayer adjacent to said first sequence of layers; a second sequence of layers of semiconductor material forming a second set of one or more solar subcells; and a high band gap contact layer adjacent said second sequence of layers, wherein the high band gap contact layer is composed of p++ type InGaAlAs or InGaAs.

Abstract: The disclosure describes multi-junction solar cell structures that include two or more graded interlayers.

Abstract: A multijunction solar cell includes an InGaAs buffer layer and an InGaAlAs grading interlayer disposed below, and adjacent to, the InGaAs buffer layer. The grading interlayer achieves a transition in lattice constant from one solar subcell to another solar subcell.