Comparison of the electronic structures of AlN nanotips grown on p- and n-type Sisubstrates

Abstract

Al and N K-edge x-ray absorption near-edge structure (XANES), scanning photoelectronmicroscopy (SPEM) and x-ray emission measurements were performed on AlNnanotips grown on p- and n-type Si substrates (p-AlN and n-AlN). Features andintensities in the Al and N K-edge XANES spectra of these AlN nanotips overall aresimilar. In contrast, the intensities of the valence-band SPEM spectra of p-AlN areapparently larger than those of n-AlN, which indicates that the valence-band density ofstates of p-AlN exceeds that of n-AlN. This result may be related to the observedenhancement of field-emission intensity of AlN nanotips grown on the p-type Si substrate.