Abstract: A method of forming a multijunction solar cell including an upper subcell, a middle subcell, and a lower subcell by providing a substrate for the epitaxial growth of semiconductor material; forming a first solar subcell on the substrate having a first band gap; forming a second solar subcell over the first solar subcell having a second band gap smaller than the first band gap; forming a graded interlayer over the second subcell, the graded interlayer having a third band gap greater than the second band gap; forming a third solar subcell over the graded interlayer having a fourth band gap smaller than the second band gap such that the third subcell is lattice mismatched with respect to the second subcell; and forming a contact composed of a sequence of layers over the first subcell at a temperature of 280° C. or less and having a contact resistance of less than 5×10?4 ohms-cm2.

Abstract: A solar cell includes a semiconductor substrate and a sequence of semiconductor layers disposed over the substrate. The sequence of semiconductor layers includes a semiconductor window layer. The solar cell also includes a semiconductor silicon-containing cap layer over the window layer. The cap layer is spatially separated from the window layer by a semiconductor barrier layer that either includes no silicon or has a silicon concentration that is significantly lower than the silicon concentration of the cap layer.

Abstract: A system for generating electrical power from solar radiation utilizing a III-V compound multijunction semiconductor solar cell; a concentrator for focusing sunlight on the solar cell; and a heat spreader connected to the solar cell for cooling the cell. The solar cell is preferably an inverted metamorphic multijunction solar cell.

Abstract: A method of forming a multifunction solar cell including an upper subcell, a middle subcell, and a lower subcell, the method including: providing a substrate for the epitaxial growth of semiconductor material; forming a first solar subcell on the substrate having a first band gap; forming a second solar subcell over the first solar subcell having a second band gap smaller than the first band gap; forming a graded interlayer over the second subcell using a non-isoelectronic surfactant such as selenium or tellurium, the graded interlayer having a third band gap greater than the second band gap; and forming a third solar subcell over the graded interlayer having 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: A system for generating electrical power from solar radiation utilizing a thin film III-V compound multijunction semiconductor solar cell mounted on a support in a non-planar configuration.

Abstract: A solar cell includes a semiconductor substrate and a sequence of semiconductor layers disposed over the substrate. The sequence of semiconductor layers includes a semiconductor window layer. The solar cell also includes a semiconductor silicon-containing cap layer over the window layer. The cap layer is spatially separated from the window layer by a semiconductor barrier layer that either includes no silicon or has a silicon concentration that is significantly lower than the silicon concentration of the cap layer.