Optical investigation of single self-organized InAs/InP quantum dashes emitting in the 1.3–1.5 µm range
Résumé
Micro-photoluminescence spectroscopy measurements have been performed on single self-organized InAs/InP quantum dashes, either on sub-micron mesas made on the sample surface or through sub-micron apertures realized in a gold mask deposited on the surface. The emission wavelength of the quantum dashes is centred around 1.5 µm at room temperature. The micro-photoluminescence measurements on sub-micron mesas, at low temperature and with low excitation power density, show PL spectra consisting of a few single sharp exciton lines with a rather large full width at half maximum (FWHM) in the 0.8–1.8 meV range, whereas peak broadening is found to be much smaller for the spectra recorded through the sub-micron apertures with an FWHM below 300 µeV. When the excitation power density is increased, new lines arise which are interpreted as emission coming from excited states of single InAs/InP quantum dashes and from bi-exciton recombination.