Low-temperature synthesis and photoluminescence of AlN

High-quality aluminum nitride powder was obtained through the reaction of a luminum metal with ammonia at 450 degrees C in an autoclave. The synthesize d powder was characterized by X-ray powder diffraction, high-resolution tra nsmission electron microscopy (HRTEM) and photoluminescence spectrum. X-ray diffraction and HRTEM indicated that the powder consisted of wurtzite AIN with an average size of about 32 nm. Photoluminescence spectrum confirmed t he existence of a blue luminescence band in AIN due to nitrogen vacancies. A possible low-temperature synthesis mechanism was discussed. (C) 1999 Else vier Science B.V. All rights reserved.