Wetting-Layer-Free AlGaN Quantum Dots for Ultraviolet Emitters

Guido Schifani (1) , Thomas Frisch (1) , Julien Brault (2) , Philippe Vennegues (2) , Samuel Matta (2) , Maxim Korytov (2) , Benjamin Damilano (2) , Jean Massies (2) , Jean-Noël Aqua (3)

1 INPHYNI - Institut de Physique de Nice
2 CRHEA - Centre de recherche sur l'hétéroepitaxie et ses applications
3 INSP - Institut des Nanosciences de Paris

We exhibit both experimentally and theoretically a novel growth mode for the epi-taxy of AlGaN quantum dots (QD), where they are eventually produced without their usual surrounding wetting layer. If the generic evolution of QD is ruled by the elastic relaxation and capillary effects, evaporation occurs here on a time scale similar to that of growth. Using a dedicated surface diffusion model accounting for elasticity, wetting and anisotropy, we evidence numerically different kinetic regimes as a function of the evaporation flux, that rationalize the experimental outcome. The resulting QD are characterized by enhanced optical properties compared to the common QD with a wetting layer. These nanostructures are promising candidates for deep ultraviolet light emitting diodes.

Mots clés: ultra-violet emitters; epitaxy; quantum dots; wetting-layer; evaporation

Domaines: Physique [physics]

Guido Schifani, Thomas Frisch, Julien Brault, Philippe Vennegues, Samuel Matta, et al.. Wetting-Layer-Free AlGaN Quantum Dots for Ultraviolet Emitters. ACS Applied Nano Materials, 2020, 3 (5), pp.4054-4060. ⟨10.1021/acsanm.9b02546⟩. ⟨hal-02883981⟩