Luminescence properties of wurtzite AlN nanotips

The optical properties of aluminum nitride nanotips (AlNNTs) synthesized via vapor transport and condensation process have been studied by cathodoluminescence, photoluminescence (PL), thermoluminescence (TL), and UV absorption measurements. Two defect related transitions around 2.1 and 3.4 eV and an excitonic feature at 6.2 eV were identified. Compared to the AlN macropowders, the AlNNTs showed a blueshift (+0.2 eV) of the similar to 3.2 eV peak. Analysis of both PL and TL excitation measurements indicated the existence of subband gap multiple energy levels in AlNNTs. A significant TL intensity even at 145 degrees C suggests possible ultraviolet detector and dosimetric applications of these AlNNTs. (c) 2006 American Institute of Physics