Blue electroluminescence from AlN nanowhiskers

AlN nanowhiskers with an average diameter of 68 nm, for which a chemical analysis showed an Al: N ratio of about 1: 0.8 and a high content of oxygen and carbon impurities, have been synthesized. The electroluminescent properties of the nanostructures have been studied at room temperature in the spectral range of 4.0–1.77 eV (310–700 nm) at varied voltage (75–200 V) and frequency (0.5–10.0 kHz) of the exciting harmonic signal. It is shown that the electroluminescence recorded in the blue spectral range is constituted by bands peaked at $E_{\mathrm{max}}\approx$ 2.53 and 2.75 eV and half-widths $\omega\approx$ 0.39 and 0.30 eV, respectively, which may be associated with electron-optical transitions involving impurity-vacancy centers in the anion and cation sublattices of AlN.