Résumé:

III-N materials have become the dominant materials for UV to blue-green semiconductor light sources. Besides these conventional light emitters, III-N materials are also attracting candidates for less conventional emitters and for new applications (integration with electronics, integration wit lab on chip, array of microsources…). In order to better control the light emission, realizing photonic nanostructures with large quality factors in the UV range is especially challenging due to the larger scattering losses compared to similar structures in the visible and IR spectral ranges. In this work we study the spectroscopy of Al(Ga)N photonic resonators embedding GaN quantum dots (QDs). For room temperature operation, nitride QDs are promising candidates due to their large radiative efficiency [1]. We have studied the spectroscopy of single photonic membrane cavities as well as microdisks, by microphotoluminescence. The recent progresses of the fabrication techniques allowed us to reach state of the art quality factors for both photonic structures, i.e. Q=1800 for a L3 nanocavity [2] and Q=7300 for microdisks [3]. In both systems, photonic modes are modelled, allowing to determine the processes limiting the quality factor. These results are compared to state of the art nitride microdisks and photonic crystal cavities.