Method for preparing compound crystal via melt migration under supergravity

A method for preparing compound crystals by melt migration under supergravity, characterized in that,

• the method comprises the following steps:
• placing a compound semiconductor polycrystal with molecular formula AxBy, a pure element A, and a seed crystal in close contact, sequentially arranged within a crucible, and positioning the crucible horizontally on a centrifugal rotation device;
• heating the crucible to T0, where 800° C.<T0<Tm, Tm being a melting point of the compound semiconductor AxBy, and T0 being greater than a melting point of element A;
• the element A melts to form a melt, and the space occupied by the melt forms a molten pool;
• a contact surface between the melt and the seed crystal forms interface I, a contact surface between the melt and the polycrystal forms interface II;
• at interface I, the melt dissolves the seed crystal, and at interface II, the melt dissolves the polycrystal, ultimately forming a non-stoichiometric melt containing element A and element B, until it reaches an equilibrium composition at a given temperature;
• a composition in the melt is C0;
• starting the centrifugal rotation device, ensuring that a centrifugal force G exceeds 100 g;
• after applying centrifugal force, elements A and B in the melt moving toward two sides of the melt pool:
• wherein the element that increases the liquid-solid phase transition equilibrium temperature moves toward interface I, the element that decreases the liquid-solid phase transition equilibrium temperature moves toward interface II, causing changes in a middle and two sides of the composition of the melt;
• due to differences in composition, the liquid-solid phase transition equilibrium temperatures at the two interfaces differ:
• at interface II, an overheating degree ΔTh is generated, causing the polycrystal to continue dissolving;
• at interface I, an overcooling degree ΔTc is generated, causing the seed crystal to begin to grow into a single crystal;
• as the polycrystal continues to dissolve and the single crystal continues to grow, the melt migrates toward the polycrystal, achieving single crystal formation.