Full text loading...
Dark field (g = 0002) TEM micrograph of (a) the 1-μm-thick InN reference sample and (b) the InN/In0.9Ga0.1 N MQW.
(a) Thermal evolution of the integrated PL emission of the analyzed InN and MQW samples emitting at ∼1.7 μm. Solid lines are fits to Eq. (1). Inset: Low temperature (T = 5 K) PL spectra of both samples. The superimposed oscillations are due to Fabry-Perot interference associated to the nitride epilayer thickness. It is worth saying that the thickness of the InN sample is much higher than the MQWs. (b) Band diagram of the InN/In0.9Ga0.1 N MQW calculated using the nextnano3 effective-mass Schrödinger-Poisson solver, assuming a residual doping level of 1019 cm−3.
Temperature dependence of the PL peak energy from (a) the InN film and (b) the MQW structure. Dashed lines indicate the theoretical evolution of the bandgap with temperature following Varshni equation, using the parameters reported in Ref. 10.
Normalized differential detected probe signal as a function of the pump-probe time delay in both InN and MQW samples for a pump peak intensity of 0.35 GW/cm2. Inset: Dependence of the initial relaxation rate 1/τini on the total electron density, which includes contributions from both background doping (n 0) and photogeneration (nexc ). The values of nexc are calculated taking into account the absorption coefficient and saturation intensity of the samples.
Activation and localization energies estimated for both InN and MQW samples.
Article metrics loading...