Suppression effect of silicon (Si) on Er3+ 1.54μm excitation in ZnO thin films

Abstract

We have investigated the photoluminescence (PL) characteristics of ZnO:Er thin films on Si (100) single crystal and SiO2-on-silicon (SiO2) substrates, synthesized by radio frequency magnetron sputtering. Rutherford backscattering/channeling spectrometry (RBS), X-ray diffraction (XRD) and atomic force microscope (AFM) were used to analyze the properties of thin films. The diffusion depth profiles of Si were determined by second ion mass spectrometry (SIMS). Infrared spectra were obtained from the spectrometer and related instruments. Compared with the results at room temperature (RT), PL (1.54μm) intensity increased when samples were annealed at 250°C and decreased when at 550°C. A new peak at 1.15μm from silicon (Si) appeared in 550°C samples. The Si dopants in ZnO film, either through the diffusion of Si from the substrate or ambient, directly absorbed the energy of pumping light and resulted in the suppression of Er3+ 1.54μm excitation. Furthermore, the energy transmission efficiency between Si and Er3+ was very low when compared with silicon nanocrystal (Si-NC). Both made the PL (1.54μm) intensity decrease. All the data in experiments proved the negative effects of Si dopants on PL at 1.54μm. And further research is going on.

Molecular dynamics simulations of the effect of shape and size of SiO2 nanoparticle dopants on insulation paper cellulose

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Near-infrared emission in Er:ZnO thin films with embedded Si nanoparticles synthesized by ion implantation

“…These observations are consistent with our earlier suggestions that the 1.54-μm PL depends on the size distribution of the formed Si-NPs, and on their coupling with Er ions. In our previous and other studies, a 1.16-μm emission has also been observed from a sample without Si implantation [30,31]. In those cases the 1.16-μm emission derives from Si diffusion from the substrate into the ZnO film.…”