Nearly defect-free InN microcrystals grown on Si(111) substrates have been realized by plasma-assisted molecular beam epitaxy. High-resolution transmission electron microscope images reveal that these microcrystals exhibit single-crystalline wurtzite structure. Low temperature photoluminescence (PL) shows a strong emission peak at 0.679 eV with a very narrow linewidth of 17 meV at excitation power density of 3.4 W cm2. Temperature-dependent PL spectra follow the Varshni equation well, and peak energy blueshifts by ∼45 meV from 300 to 15 K. Power-density-dependent PL spectroscopy manifests direct near-band-edge transition. A low carrier density of 3× 1017 cm-3 has been estimated from PL empirical relation, which is close to the critical carrier density of the Mott transition of 2× 1017 cm-3.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)