Abstract: A solar cell with spaced apart groupings of self-assembled quantum dot layers interposed with barrier layers. Such groupings allow improved control over the growth front quality of the solar cell, the crystalline structure of the solar cell, and on the performance metrics of the solar cell.

Abstract: A solar cell and a method of fabricating solar cells. The method includes a step of separating neighbor solar cells formed on a semiconductor wafer by scribing the wafer to form scribe lines on the wafer and applying a force at, or adjacent to, the scribed lines to separate the solar cells. The scribing is effected on a cap layer covering a window layer of solar cells, thereby minimizing damage to the window layer and mitigating propagation of defects into p-n junctions formed in the solar cells.

Abstract: A multi junction solar cell having epitaxially-deposited III/V compounds on vicinal group IV substrates and method for making same. The solar cell includes an AlAs nucleating layer on a Ge substrate. The group IV substrate contains a p-n junction whose change of characteristics during epitaxial growth of As-containing layers is minimized by the AlAs nucleating layer. The AlAs nucleating layer provides improved morphology of the solar cell and a means to control the position of a p-n junction near the surface of the group IV substrate through diffusion of As and/or P and near the bottom of the III/V structure through minimized diffusion of the group IV element.

Abstract: An apparatus and method to electrically and optically characterize a multijunction solar cell. The apparatus can have as many light sources as there are subcells in the multijunction solar cell. Each light source has an optical spectrum that falls within the bandgap energy of a corresponding subcell. Each light source has a controllable intensity level.

Abstract: Electronic and opto-electronic devices having epitaxially-deposited III/V compounds on vicinal group IV substrates and method for making same. The devices include an AlAs nucleating layer on a Ge substrate. The group IV substrate contains a p-n junction whose change of characteristics during epitaxial growth of As-containing layers is minimized by the AlAs nucleating layer. The AlAs nucleating layer provides improved morphology of the devices and a means to control the position of a p-n junction near the surface of the group IV substrate through diffusion of As and/or P and near the bottom of the III/V structure through minimized diffusion of the group IV element.

Abstract: An apparatus to electrically and optically characterize a multijunction solar cell. The apparatus can have as many light sources as there are subcells in the multijunction solar cell. Each light source has an optical spectrum that falls within the bandgap energy of a corresponding subcell. Each light source has a controllable intensity level.

Abstract: Electronic and opto-electronic devices having epitaxially-deposited III/V compounds on vicinal group IV substrates and method for making same. The devices include an AlAs nucleating layer on a Ge substrate. The group IV substrate contains a p-n junction whose change of characteristics during epitaxial growth of As-containing layers is minimized by the AlAs nucleating layer. The AlAs nucleating layer provides improved morphology of the devices and a means to control the position of a p-n junction near the surface of the group IV substrate through diffusion of As and/or P and near the bottom of the III/V structure through minimized diffusion of the group IV element.

Abstract: A monolithic semiconductor photovoltaic solar cell comprising a plurality of subcells disposed in series on an electrically conductive substrate. At least one subcell of the plurality of subcells includes an epitaxially grown self-assembled quantum dot material. The subcells are electrically connected via tunnel junctions. Each of the subcells has an effective bandgap energy. The subcells are disposed in order of increasing effective bangap energy, with the subcell having the lowest effective bandgap energy being closest to the substrate. In certain cases, each subcell is designed to absorb a substantially same amount of solar photons.