Emission from quantum-well InGaAs structures

An experimental investigation was made of the spontaneous emission spectra of InGaAs laser structures based on strained quantum wells. The density of the injection current was up to similar to 9.2 kA cm(-2) and the investigation was carried out in the temperature range 4.2-286 K. The energy of the emitted photons was 1.2-1.5 eV. The spectrum was dominated by the 1e-1hh transition and the peak representing this transition was practically independent of the current. There was no evidence of the 'red' shift predicted by the many-body theory for high carrier concentrations. Weak forbidden transitions (1e-2hh, etc.) were identified. The long-wavelength edge of the emission band varied exponentially in accordance with the familiar Urbach rule for the absorption edge.