Abstract: In growing a single-crystal silicon by the present invention in a Czochralski method, after a surface of a silicon melt is brought into contact with a seed crystal in a crucible, the silicon melt being added with germanium, the single-crystal silicon is pulled while rotated, and the solar-cell single-crystal silicon substrate is sliced from the single-crystal silicon containing germanium, whereby a germanium content of solar-cell single-crystal silicon substrate is set in the range of not less than 0.03 mole % to less than 1.0 mole % when resistivity ranges from 1.4 to 1.9 ?cm. Therefore, conversion efficiency is enhanced when compared with conventional single-crystal silicon substrates. Accordingly, solar cell power generation costs decreases, so that the single-crystal silicon of the present invention can widely be utilized as the substrate for the solar cell in which the high conversion efficiency is increasingly demanded.

Abstract: A multi-crystalline silicon germanium bulk crystal with microscopic compositional distribution is adapted for use in solar cells to substantially increase conversion efficiency. By controlling the average Ge concentration between 0.1 and 8.0 mole percent, significant improvements are attained with respect to short circuit current density and conversion efficiency.

Abstract: Provided is a multi-element polycrystal formed by cooling a melt containing multiple components while controlling a cooling rate. The multi-element polycrystal is a mixed crystal essentially formed of elements Si and Ge having different absorption wavelength ranges and having a composition represented by Si1-XGeX, in which Ge absorbs light over a longer range of wavelength from a shorter to longer wavelength range than Si, each of the crystal grains of the mixed crystal has a matrix having a plurality of discrete regions dispersed therein, the average matrix composition is represented by Si1-x1Gex1 and the average composition of the discrete regions is represented by Si1-x2Gex2 where X1<X<X2. Also, provided is a solar-cell polycrystal satisfying high light-absorption efficiency and low cost by using the multi-element polycrystal, a solar cell and a method of manufacturing the solar cell.

Abstract: In growing a single-crystal silicon by the present invention in a Czochralski method, after a surface of a silicon melt is brought into contact with a seed crystal in a crucible, the silicon melt being added with germanium, the single-crystal silicon is pulled while rotated, and the solar-cell single-crystal silicon substrate is sliced from the single-crystal silicon containing germanium, whereby a germanium content of solar-cell single-crystal silicon substrate is set in the range of not less than 0.1 mole % and less than 1.0 mole %. Desirably the germanium content is set in the range of not less than 0.1 mole % to not more than 0.6 mole %, and the germanium content is set in the range of not less than 0.03 mole % to less than 1.0 mole % when resistivity ranges from 1.4 to 1.9 ?cm. Therefore, conversion efficiency can largely be enhanced compared with the case where the conventional single-crystal silicon substrate is used.

Abstract: A multi-crystalline silicon germanium bulk crystal with microscopic compositional distribution is adapted for use in solar cells to substantially increase conversion efficiency. By controlling the average Ge concentration between 0.1 and 8.0 mole percent, significant improvements are attained with respect to short circuit current density and conversion efficiency.

Abstract: Provided is a multi-element polycrystal formed by cooling a melt containing multiple components while controlling a cooling rate. The multi-element polycrystal is a mixed crystal essentially formed of elements Si and Ge having different absorption wavelength ranges and having a composition represented by Si1-XGeX, in which Ge absorbs light over a longer range of wavelength from a shorter to longer wavelength range than Si, each of the crystal grains of the mixed crystal has a matrix having a plurality of discrete regions dispersed therein, the average matrix composition is represented by Si1-x1Gex1 and the average composition of the discrete regions is represented by Si1-x2Gex2 where X1<X<X2. Also, provided is a solar-cell polycrystal satisfying high light-absorption efficiency and low cost by using the multi-element polycrystal, a solar cell and a method of manufacturing the solar cell.

Abstract: Optical resonators are vertically coupled on top of bus waveguides, and are separated from the waveguides by a buffer layer of arbitrary thickness. The vertical arrangement eliminates the need for etching fine gaps to separate the rings and guides, and reduces the alignment sensitivity between the desired position of the resonator and bus waveguides by a significant degree. The resonator and bus waveguides lie in different vertical layers, and each can therefore be optimized independently. A ring resonator can be optimized for higher index contrast in the plane, small size, and low bending loss, while the bus waveguides can be designed to have lower index contrast in the plane, low propagation losses, and dimensions that make them suitable for matching to optical fibers. The waveguides can also have any lateral placement underneath the ring resonators and are not restricted by the placement of the rings.