Skip to Main content Skip to Navigation
Journal articles

The low temperature limit of the excitonic Mott density in GaN: an experimental reassessment

Abstract : The research on GaN lasers aims for a continuous reduction of the lasing threshold. An approach to achieve it consists in exploiting stimulated polariton scattering. This mechanism, and the associated polariton lasers, requires an in-depth knowledge of the GaN excitonic properties, as polaritons result from the coupling of excitons with photons. Under high excitation intensities, exciton states no longer exist due to the Coulomb screening by free carriers; this phenomenon occurs at the so-called Mott density. The aim of this work is to study the bleaching of excitons under a quasi-continuous optical excitation in a bulk GaN sample of high quality through power dependent micro-photoluminescence and time-resolved experiments at 5 K. Time-resolved photoluminescence allows to measure the carrier lifetime as a function of excitation intensity, which is required for a reliable evaluation of the injected carrier density. The vanishing of excitonic lines together with the red-shift of the main emission evidences the occurrence of the Mott transition for a carrier concentration of (6 ± 3) × 10 16 cm −3. This value is more than an order of magnitude smaller than previous determinations published in the literature and is in accordance with many-body calculations.
Complete list of metadata
Contributor : Blandine Alloing Connect in order to contact the contributor
Submitted on : Wednesday, March 23, 2022 - 11:54:37 AM
Last modification on : Thursday, August 4, 2022 - 5:05:53 PM
Long-term archiving on: : Friday, June 24, 2022 - 6:54:50 PM


Publisher files allowed on an open archive



Léo Mallet-Dida, Pierre Disseix, François Réveret, François Médard, Blandine Alloing, et al.. The low temperature limit of the excitonic Mott density in GaN: an experimental reassessment. New Journal of Physics, Institute of Physics: Open Access Journals, 2022, 24, pp.033031. ⟨10.1088/1367-2630/ac58b9⟩. ⟨hal-03617195⟩



Record views


Files downloads