Abstract: AlN polycrystalline boules with a diameter of 40～50mm, a thickness of 8～10mm,and a grain size of up to 5mm have been grown with physical vapor transport technology.The crystalline quality,defects,and structure of these crystals have been investigated by using Raman scattering and cathodoluminescence spectroscopy.The electrical conductivity of the AlN crystal has been measured from room temperature to 800℃,and a deep level defect with activation energy of 0.98eV is identified.The influence of growth conditions on AlN crystalline quality is also discussed.

Key words: AlN, physical vapor transport, defects