Sharp Infrared Emission from Single‐Crystalline Indium Nitride Nanobelts Prepared Using Guided‐Stream Thermal Chemical Vapor Deposition

Abstract

Single‐crystalline InN nanobelts have been synthesized using Au as the catalyst by a guided‐stream thermal chemical vapor deposition technique. The resultant InN nanobelts typically have widths ranging from 20 to 200 nm, a width to thickness ratio of 2–10, and lengths of up to several tens of micrometers. Structural analysis shows that these InN nanobelts have a wurtzite structure and exhibit a rectangular cross section with self‐selective facets, i.e., the nanobelts are enclosed only by ± (001) and ± (11?0) planes with [110] being the exclusive growth direction along their long axis. This facet selectivity can be understood by the differences in the surface energies of the different facets. Photoluminescence (PL) spectra of InN nanobelts show a sharp infrared emission peak at 0.76 eV with a full width at half maximum of 14 meV, narrower than the values reported for InN epilayers. The integrated PL intensity is found to increase linearly with the excitation power, which suggests that the observed PL can be attributed to direct band‐to‐band emission.

InN layers grown by MOCVD on substrates

“…The integrated PL intensity increases linearly with the excitation power over two orders of magnitude, as shown in the inset of Fig. 5(a), which is consistent with the fundamental interband transition in direct band gap semiconductor [14,15]. The temperature dependent PL was measured from 12 to 290 K, shown in Fig.…”

Soft-x-ray spectroscopy probes nanomaterial-based devices

“…The ribbon-like nanobelts have widths of ∼20-80nm, width to thickness ratios of 2-10, and lengths of ∼15um. 5 The electronic structures of the film and nanobelts occur at the same energy and exhibit similar spectral profiles, which indi- cates that the local symmetry and chemical states are similar. The intensities of these features are quite different, however, implying the stronger anisotropy of the p-state in the conduction band of the thin film.…”

“…Furthermore, it has been found recently that the band gap of InN is ∼0.7-0.9eV and not ∼1.9eV as it has long been believed. 5,6 Figure 4 displays the nitrogen (N) K-edge XAS for InN film and nanobelts recorded at different incidence angles. The ribbon-like nanobelts have widths of ∼20-80nm, width to thickness ratios of 2-10, and lengths of ∼15um.…”

Growth of AlN nanobelts, nanorings and branched nanostructures

“…Since the discovery of semiconducting oxides nanobelts [1], belt-like nanomaterials have attracted great attention due to their unique geometries, novel physical and chemical properties, and potential applications in nanoscale electronics and photonics [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Some devices including field-effect transistors [16], ultrasensitive gas sensors [17], and resonators [18] have been fabricated based on individual nanobelts.…”