A polycrystalline silicon ingot having a value of T.sub.eT.sub.s, T, of 50 C. or less, wherein T.sub.s and T.sub.e are the onset temperature and the completion temperature of melting, respectively, when the temperature is increased at a rate of 60 C./minute or less in the temperature range of 1400 C. or more is used as the production raw material for single crystal silicon. The present invention provides a polycrystalline silicon ingot or polycrystalline silicon rod suitable for stably producing single crystal silicon.

A polycrystalline silicon ingot having a value of T.sub.eT.sub.s, T, of 50 C. or less, wherein T.sub.s and T.sub.e are the onset temperature and the completion temperature of melting, respectively, when the temperature is increased at a rate of 60 C./minute or less in the temperature range of 1400 C. or more is used as the production raw material for single crystal silicon. The present invention provides a polycrystalline silicon ingot or polycrystalline silicon rod suitable for stably producing single crystal silicon.

A method of fabricating at least one single-crystal alloy semiconductor structure, comprising: forming at least one seed on a substrate for growth of at least one single-crystal alloy semiconductor structure, the at least one seed containing an alloying material; providing at least one structural form on the substrate which is crystallized to form the at least one single-crystal alloy semiconductor structure, the at least one structural form being formed of a host material and comprising a main body which extends from the at least one seed and a plurality of elements which are connected in spaced relation to the main body; heating the at least one structural form such that the material of the at least one structural form has a liquid state; and cooling the at least one structural form, such that the material of the at least one structural form nucleates at the least one seed and crystallizes as a single crystal to provide at least one single-crystal alloy semiconductor structure, with a growth front of the single crystal propagating in the main body of the respective structural form away from the respective seed; wherein the plurality of elements of each structural form provide reservoirs of the alloying material in liquid state, such that successive ones of the plurality of elements act to maintain, in liquid state, an available supply of the alloying material to the growth front of the single crystal in the main body of the respective structural form.

A method of fabricating at least one single-crystal alloy semiconductor structure, comprising: forming at least one seed on a substrate for growth of at least one single-crystal alloy semiconductor structure, the at least one seed containing an alloying material; providing at least one structural form on the substrate which is crystallized to form the at least one single-crystal alloy semiconductor structure, the at least one structural form being formed of a host material and comprising a main body which extends from the at least one seed and a plurality of elements which are connected in spaced relation to the main body; heating the at least one structural form such that the material of the at least one structural form has a liquid state; and cooling the at least one structural form, such that the material of the at least one structural form nucleates at the least one seed and crystallizes as a single crystal to provide at least one single-crystal alloy semiconductor structure, with a growth front of the single crystal propagating in the main body of the respective structural form away from the respective seed; wherein the plurality of elements of each structural form provide reservoirs of the alloying material in liquid state, such that successive ones of the plurality of elements act to maintain, in liquid state, an available supply of the alloying material to the growth front of the single crystal in the main body of the respective structural form.

Disclosed herein is a single nonlinear optical crystal having a chemical formula of MgIVV2, wherein IV is selected from Si, Ge, or Sn, and V is selected from P or As, wherein the single nonlinear optical crystal has a chalcopyrite and non-centrosymmetric crystal structure, with a space group of, wherein the non-centrosymmetric crystal structure is defined by unit cell parameters: a between about 5.5 to about 6 , c between about 9.5 to about 12.5 , and a unit cell volume of about 287 to about 450 .sup.3, wherein the single nonlinear optical crystal exhibits a refractive index of about 2.770 to about 2.780 and from about 2.800 to about 2.810 for no and ne respectively at a wavelength of 1,550 nm, and a nonlinear coefficient of d.sub.eff of SHG from about 80 to about 95 pm/V, wherein the single crystal MgIVV.sub.2 is substantially free of impurities.