Photoluminescence and absorption spectroscopy of silicon-doped InGaN layers

Silicon-doped InxGa1−xN films (0.01≲x≲0.03) have been grown by metalorganic vapour phase epitaxy on sapphire substrates. The evolution of the photoluminescence (PL) lineshape has been studied as a function of temperature and electron concentration n. PL linewidths are related to n by a power law. High-energy slopes of PL spectra indicate quasi-thermal equilibrium at room temperature justifying the use of the van Roosbroeck–Shockley (vRS) relation to link both absorption and PL. Absorption characteristics as implied by this relation are compared with experimental absorption spectra.