Micro-Raman Investigation of Nanocrystalline GaN, AlN, and an AlGaN composite Prepared from Pyrolysis of Metal Amide-Imide Precursors

摘要

In this communication, the impact of precursor pyrolysis temperature on the Raman spectroscopic properties of nanophase GaN derived from the polymeric gallium imide (Ga(NH)3/2)n is reported. GaN prepared by pyrolysis at either 900 or 1100 deg C exhibit modes at approx. 570 and 730 /cm consistent with the presence of hexagonal GaN. Employing a lower conversion temperature of 700 deg C produces a lattice with extensive defects, as evidenced by the prescence of additional bands at 332, 410, 637, and 744 /cm; additional heating of this type of sample at 900 and 1000 deg C diminishes the intensity of these defect-related modes. Raman spectra of nanophase aluminum nitride (AlN) and an aluminum gallium nitride (AlGaN) composite prepared from pyrolysis of the requisite precursors at a fixed temperature of 900 deg C are also presented.