TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The A1xBx is Si1xGex. The C1xDxE is Ga1xInxAs. Preferred Condition: The crystal grains have a columnar shape. The discrete regions are three-dimensionally dispersed in the matrix having strain. Preferred Composition: The melt has a composition for a mixed crystal is represented by A1xBx or C1xDxE, where the element B absorbs light over a longer range of wavelength from a shorter to longer wavelength range than the element A, and each of the polycrystal grains manufactured has a crystallographic texture in which discrete regions having an average composition represented by A1-x2Bx2 or C1-x1Dx1E are dispersed in a matrix having an average composition represented by A1-xBx or C1x2Dx2E.x=greater than x1 but less than x2;C=Ga;D=In;E=As.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The A1xBx is Si1xGex. The C1xDxE is Ga1xInxAs. Preferred Condition: The crystal grains have a columnar shape. The discrete regions are three-dimensionally dispersed in the matrix having strain. Preferred Composition: The melt has a composition for a mixed crystal is represented by A1xBx or C1xDxE, where the element B absorbs light over a longer range of wavelength from a shorter to longer wavelength range than the element A, and each of the polycrystal grains manufactured has a crystallographic texture in which discrete regions having an average composition represented by A1-x2Bx2 or C1-x1Dx1E are dispersed in a matrix having an average composition represented by A1-xBx or C1x2Dx2E.x=greater than x1 but less than x2;C=Ga;D=In;E=As. Preferred Definitions:    x=less than or equal to0.1;    A=Si;    B=Ge    EXAMPLE - Silicon (1.66 g) and germanium (3.71 g) were mixed and melted to prepare a melt of a two-element silicon germanium system having a uniform composition. The melt was cooled at a predetermined cooling rate to obtain a polycrystal formed of crystal particles each having a crystallographic texture in which germanium-rich regions was dispersed in a silicon-rich matrix.