Red–green–blue light emission and energy transfer processes in amorphous SiN films doped with Sm and Tb

Abstract

Amorphous silicon-nitrogen (a-SiN) thin films have been independently doped with Sm, Tb, and Sm + Tb. The films were prepared by reactive cosputtering and characterized by energy dispersive x-ray analysis, optical transmission, and photo-and cathodoluminescence techniques. All films display roomtemperature visible luminescence after excitation with either photon or electron sources. The present results indicate that the luminescence intensity is highly susceptible to thermal annealing treatments as well as to the combination of rare-earth ions. In fact, an improvement of about 500% was achieved in the overall optical emission after annealing the films up to 1050 • C for 15 min. Also, the presence of Tb 3+ ions in the Sm + Tb-doped a-SiN films enhanced the Sm 3+ -related emission, and spectrally sharp optical transitions could be verified at 485, 545, and 650 nm. The likely mechanisms behind the optical activation of the Sm 3+ and Tb 3+ ions and the energy transfer processes between these ions and the amorphous SiN matrix, are presented and discussed. In order to improve the blue light emission of the present samples, one a-SiN film simultaneously doped with Sm + Tb + Tm has also been prepared and investigated in detail.

Cathodoluminescence from Amorphous and Nanocrystalline Nitride Thin Films Doped with Rare Earth and Transition Metals

“…3.3). As reported by Zanatta et al (Zanatta, Khan et al 2007) a-SiN doped with Sm and Tb exhibit significant enhancements of 4f-shell radiative recombinations upon thermal annealing due to a decrease in the density of deep and/or tail defects (suppression of the nonradiative processes). A similar observation was made for a-AlN:Ho system (Aldabergenova, Frank et al 2006).…”

Visible Luminescence of Rare Earth Ions Doped Amorphous Zinc Oxide Thin Films Grown by Sputtering Technique

“…The XRD spectra of as-grown a-ZnO/c-Si (100) can be found in [9]. We believe that the RE ions concentration in films studied here is below 1 at.% [11]. However, the XRD spectra of quartz/ZnO:Sm thin films show diffuse scattering centered at ~24° which is coming from the substrate.…”

Studies of Ni and Co Doped Amorphous AlN for Magneto-optical Applications

“…We have studied the surface of selected samples with TEM and AFM to elucidate if the surface of studied films changed upon annealing. Furthermore, it is documented in the literature that thermally annealed amorphous semiconductors experience some structural reordering (not necessarily crystallization) [13,14]. Figure 3 shows TEM images of a-AlN sample with largest Ni at.%.…”