We have studied the recombination mechanism of InGaAs/GaAs V-shaped quantum wire lasers under electrical injection and in high magnetic field, from well below to above lasing threshold. The emission originates from free-carrier recombination independent of temperature and injection density. No excitonic contribution is found, indicating that excitons are weakly bound in these wires due to the internal piezoelectric field causing a strong Stark effect. A quantitative analysis of the piezoelectric field is performed by measuring the screening induced blue-shift of the electroluminescence at different densities and comparing it with the piezoelectric potential calculated from the quantum wire cross-sections observed by transmission electron microscopy.
Devittorio, M., Rinaldi, R., Passaseo, A., Degiorgi, M., Lomascolo, M., Visconti, P., … Tapfer, L. (1999). Recombination in InGaAs/GaAs quantum wire lasers. Solid State Communications, 112(1), 55–60. https://doi.org/10.1016/S0038-1098(99)00234-3