NOVELTY - Growing crystalline gallium-containing nitride involves providing capsule containing gallium-containing feedstock in one zone and seed in another zone; maintaining elevated pressure within the capsule, introducing first solvent capable of forming supercritical fluid into the zone; placing capsule within high pressure apparatus; processing portion of gallium-containing feedstock in the fluid to provide supercritical solution containing gallium having species at first temperature; and growing crystalline gallium-containing nitride material from solution on seed at second temperature.    USE - For growing crystalline gallium-containing nitride, used in optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation, photodetectors, integrated circuits, and transistors.    ADVANTAGE - The method is large-scale manufacturing method; reduces or minimizes contamination in the crystals; improves or optimizes solvent atmosphere composition; is able to recycle the solvent; is scalable up to large volumes; and is simple and cost effective method.    DETAILED DESCRIPTION - Growing a crystalline gallium-containing nitride involves providing a high pressure apparatus; providing autoclave or capsule containing gallium-containing feedstock in one zone and at least one seed in another zone; while maintaining an elevated pressure within the capsule, introducing first solvent capable of forming a supercritical fluid into at least one zone and the other zone; placing the capsule within the high pressure apparatus; processing at least one portion of the gallium-containing feedstock in the supercritical fluid to provide a supercritical solution containing at least gallium having species at a first temperature; growing crystalline gallium-containing nitride material from the supercritical solution on the seed at a second temperature, where the second temperature is characterized to cause the gallium containing species to form the crystalline gallium containing nitride material on the seed; removing thermal energy from the autoclave or capsule to form a second solvent from the supercritical solution; and removing the second solvent from the autoclave or capsule through an outlet; and transferring the second solvent from the outlet to a purification process.    DESCRIPTION OF DRAWING(S) - The figure shows flow chart of method of solvent removal and recycling.