Abstract: An apparatus and method for making a solar cell with an integrated bypass diode. The method comprises the steps of depositing a second layer having a first type of dopant on a first layer having an opposite type of dopant to the first type of dopant to form a solar cell, depositing a third layer having the first type of dopant on the second layer, depositing a fourth layer having the opposite type of dopant on the third layer, the third layer and fourth layer forming a bypass diode, selectively etching the third layer and the fourth layer to expose the second layer and the third layer, and applying contacts to the fourth layer, third layer, and the first layer to allow electrical connections to the assembly.

Abstract: A multilayer semiconductor structure includes a germanium substrate having a first surface. The germanium substrate has two regions, a bulk p-type germanium region, and a phosphorus-doped n-type germanium region adjacent to the first surface. A layer of a phosphide material overlies and contacts the first surface of the germanium substrate. A layer of gallium arsenide overlies and contacts the layer of the phosphide material, and electrical contacts may be added to form a solar cell. Additional photovoltaic junctions may be added to form multijunction solar cells. The solar cells may be assembled together to form solar panels.

Abstract: An improved photovoltaic cell has an active silicon (Si) or silicon-germanium (SiGe) substrate subcell having an active upper side and characterized by a substrate bandgap. One or more upper subcells are disposed adjacent the upper side and current matched with the substrate subcell, with the upper subcell(s) typically having bandgap(s) greater than the substrate bandgap. A transition layer may be placed intermediate the upper side and the upper subcell(s).

Abstract: A multijunction photovoltaic cell comprises a first subcell that initially receives incident light upon the photovoltaic cell, with the first subcell being made of a first material system, having a first thickness, and producing a first photogenerated current output. A second subcell receives the incident light after the first subcell receives the incident light, with the second subcell being disposed immediately adjacent the first subcell. The second subcell is made of the first material system or a similar semiconductor material, has a second thickness that is greater than the first thickness, and produces a second photogenerated current output that is substantially equal in amount to the first photogenerated current output. A tunnel junction is disposed between the first and second subcells. The multijunction cell provides a greater ability to current match to low-current-producing subcells, higher multijunction cell voltage, lower series resistance, and greater radiation resistance.

Abstract: An improved photovoltaic cell, according to one embodiment, includes a base layer; a primary window layer having a first type of doping, with the primary window layer being disposed over the base layer; and a secondary window layer having the first type of doping, with the secondary window layer being disposed over the primary window layer. In another embodiment, the improved photovoltaic cell has a multilayer back-surface field structure; a base layer disposed over the back-surface field structure; and a primary window layer disposed over the base layer. In yet another embodiment, the photovoltaic cell includes a base layer; and a primary window layer disposed over the base layer, with the primary window layer having a thickness of at least about 1000 Angstroms.

Abstract: A semiconductor P-I-N detector including an intrinsic wafer, a P-doped layer, an N-doped layer, and a boundary layer for reducing the diffusion of dopants into the intrinsic wafer. The boundary layer is positioned between one of the doped regions and the intrinsic wafer. The intrinsic wafer can be composed of CdZnTe or CdTe, the P-doped layer can be composed of ZnTe doped with copper, and the N-doped layer can be composed of CdS doped with indium. The boundary layers is formed of an undoped semiconductor material. The boundary layer can be deposited onto the underlying intrinsic wafer. The doped regions are then typically formed by a deposition process or by doping a section of the deposited boundary layer.

Abstract: An improved photovoltaic cell, according to one embodiment, includes a base layer; a primary window layer having a first type of doping, with the primary window layer being disposed over the base layer; and a secondary window layer having the first type of doping, with the secondary window layer being disposed over the primary window layer. In another embodiment, the improved photovoltaic cell has a multilayer back-surface field structure; a base layer disposed over the back-surface field structure; and a primary window layer disposed over the base layer. In yet another embodiment, the photovoltaic cell includes a base layer; and a primary window layer disposed over the base layer, with the primary window layer having a thickness of at least about 1000 Angstroms.

Abstract: A heteroepitaxial semiconductor device having reduced density of threading dislocations and a process for forming such a device. According to one embodiment, the device includes a substrate which is heat treated to a temperature in excess of 1000.degree. C., a film of arsenic formed on the substrate at a temperature between 800.degree. C. and 840.degree. C., a GaAs nucleation layer of less than 200 angstroms and formed at a temperature between about 350.degree. C. and 450.degree. C., and a plurality of stacked groups of layers of InP, wherein adjacent InP layers are formed at different temperatures.