High Efficiency White Luminescence of Alumina doped ZnO

Alban A. Letailleur (1, 2, 3) , Sergey Yu Grachev (1) , Etienne Barthel (1) , Elin Sondergard (1) , Komla Nomenyo (2) , Christophe Couteau (2) , Stefan Mc Murtry (2) , Gilles Lerondel (2) , Emilie Charlet (4) , Emmanuelle Peter (4)

1 SVI - Surface du Verre et Interfaces
2 LNIO - Laboratoire de Nanotechnologie et d'Instrumentation Optique
3 LCMCP (site Paris VI) - Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI)
4 Thin Films Division

The application of Alumina-doped ZnO (AZO) films as luminescent material for large area lighting sources has been evaluated. Thin films were grown on quartz using magnetron sputtering and subsequently annealed under argon atmosphere in a rapid thermal annealing experiment. Below 550 °C, red-shift of the optical band gap and increase of the visible emission are observed in agreement with Al diffusion and formation of interstitial oxygen atoms. At temperatures higher than 800 °C, diffusion is activated and Ostwald ripening leads to the formation of larger grains and an increase of the crystalline phase. The photoluminescence (PL) intensity is enhanced, specifically in the UV range. As a result the emission spectrum of AZO thin films can be adjusted by the annealing conditions, with equal contributions from the UV and orange parts of the PL spectrum resulting in an efficient white emission as quantified using the color space map of the Commission Internationale de l'Éclairage.

Mots clés: White luminescence; Rapid annealing; Doping; Zinc oxide

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Alban A. Letailleur, Sergey Yu Grachev, Etienne Barthel, Elin Sondergard, Komla Nomenyo, et al.. High Efficiency White Luminescence of Alumina doped ZnO. Journal of Luminescence, 2011, 131 (12), pp.2646-2651. ⟨10.1016/j.jlumin.2011.06.044⟩. ⟨hal-00602889⟩