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effects on the photoluminescence of terbium doped zinc oxide films. Thin Solid Films, Elsevier, 2014Elsevier, , 553, pp.52-57. 10.1016Elsevier, /j.tsf.2013 Annealing effects on the photoluminescence of terbium doped zinc oxide films Terbium doped zinc oxide (Tb:ZnO) films were deposited by radio frequency magnetron sputtering on (100) single-crystalline silicon substrates at low temperature (T S = 100°C). In this work, structural changes, optical properties and the associated photoluminescence (PL) responses are analyzed upon the annealing treatments. Post-annealing treatments from annealing temperature T a = 400°C up to 1000°C by steps of 100°C were performed. Chemical analyses by energy dispersive X-ray spectrometry measurements showed a constant dopant concentration of 3 at.%. Up to 600°C, the band gaps (E g ) decreased with T a from 3.44 down to 3.37 eV. Above 600°C, the band gap raised from 3.37 up to 3.42 eV (for 900°C). Depending on T a , a bi-axial stress was found varying from a compressive value of −0.21 GPa (400°C) down to a tensile value of 0.05 GPa (1000°C). PL mechanisms of the Tb:ZnO film are then discussed.

International audienceIn this paper, we will present the development of rareearth(RE) doped zinc oxide (ZnO) films for white lightemitting diodes (LED). We will present the structuralchanges of these films as well as their optical propertiesand associated photoluminescence before and after rapidthermal treatments. We will report depth profile resultsfrom plasma profiling time of flight mass spectrometry(PP-TOFMS) giving the distributions and concentrationsof the different elements in the films. We will correlatedepth profile and luminescence data to understand the REemission mechanisms in ZnO matrix

Cobalt doped ZnO (ZnO:Co) films with a 1 at% doping rate have been successfully grown on (100) oriented p type Si substrates by radiofrequency magnetron sputtering. Post annealing treatments at 973 K for various short periods have been carried out and structural, optical and electrical properties of the films have been investigated. Upon rapid annealing, the dopant distribution in the film has been found homogeneous. The annealing improves the (002) texture of the film and the mean column width increases with the annealing duration from 60 nm up to 95 nm. The lattice parameter of the ZnO:Co films decreases upon annealing and approaches that of bulk ZnO. The photoluminescence (PL) study reveals that the Co2+ ions can be excited directly or through a transfer mechanism from the matrix. The PL intensity decreases with the annealing time suggesting a diffusion process of the dopant impeding the Co2+ emission. At last, the electrical conductivity reaches values compatible with potential electroluminescent applications of the ZnO:Co films.