Abstract: Electrically conducting bulk ?-Ga2O3 single crystals can be produced by the Czochralski (CZ) method to have a pre-defined cylindrical diameter and a pre-defined cylindrical length. The method uses a growth furnace having a noble metal crucible with a Ga2O3 starting material. An inner thermal insulation is provided in the growth furnace with a radiative reflectivity lower than 0.4 in a near infrared spectral region of 1-3 ?m to decrease reflections of heat back to the growing single crystal, and thus, to increase the heat dissipation from the growing single crystal. Also, in the CZ method, when puling a single crystal from seeding to separation, a dynamic decrease of the growth rate is achieved from the initial growth rate of 1-10 mm/h, to a final growth rate of 0.2-1 mm/h, to dynamically decrease the latent heat of crystallization as the growth proceeds.

Abstract: A method for producing crystals and/or crystal materials is described whereby the undesirable impurities are removed from the crystal and/or the material with the aid of a purification agent or getter. Elemental fluorine and/or a reactive fluorine-containing substance is used as the purification agent or getter. Preferred getters are XeF2 and/or carbon fluoride. Crystals obtained in this manner are suitable for use as optical components.