Provided are a P-type ZrCoSb-based half-Heusler single crystal alloy and a preparation method thereof. The method for preparing the P-type ZrCoSb-based half-Heusler single crystal alloy includes: subjecting alloy raw materials to smelting under a first protective atmosphere to obtain a half-Heusler polycrystalline alloy ingot, the alloy raw materials corresponding to a chemical composition of the P-type ZrCoSb-based half-Heusler single crystal alloy; and subjecting the half-Heusler polycrystalline alloy ingot to vertical Bridgman directional crystallization under a second protective atmosphere to obtain the P-type ZrCoSb-based half-Heusler single crystal alloy. The P-type ZrCoSb-based half-Heusler single crystal alloy has the chemical composition of ZrCoSb.sub.1-xSn.sub.x, x in the ZrCoSb.sub.1-xSn.sub.x being in a range of 0.1x0.3; and the P-type ZrCoSb-based half-Heusler single crystal alloy has an MgAgAs-type crystal structure.

A single crystal growth method for growing a single crystal of a gallium oxide-based semiconductor, the method including growing the single crystal from a melt of a raw material of the single crystal in an oxidizing atmosphere. Density and average length of voids in the single crystal are controlled by a relative value of an Si concentration and an Sn concentration in the single crystal.

A single crystal growth method for growing a single crystal of a gallium oxide-based semiconductor, the method including growing the single crystal from a melt of a raw material of the single crystal in an oxidizing atmosphere. Density and average length of voids in the single crystal are controlled by a relative value of an Si concentration and an Sn concentration in the single crystal.