Figure 4
WGM-related narrow lines in μ-PL spectra measured in InN structures.
(a) The inset demonstrates the spot of a laser beam (532 nm), which can be focused either on the top surface of a crystal (p. 1) or on the area between the cones (p. 2). No narrow lines were observed in the latter case. The energies of the narrow lines are not identical in the crystals of different sizes: A (d = 2.2 μm) and B (d = 1.2 μm). (b) μ-PL spectra of the crystal C (d = 2.2 μm) measured at 77 K and 300 K, shown together with integral absorption spectra (dashed lines). The narrow line energies at a distance from the absorption edge are identical at different temperatures. Theoretical energies are marked at the bottom axes in (a,b) (see text for details). (c) μ-PL spectra measured in different crystals with 
μm, exhibiting the similar energies of the narrow lines.
