Simplified Synthesis and Luminous Mechanism of Eu²⁺-Doped α-Si₃N₄ Nanowires with Strong Green Luminescent Properties

Abstract

Ultra-long, single crystal, Eu-doped α-Si3N4 nanowires were prepared by a simple approach involving nitriding Eu-doped cryomilled nanocrystalline Si powder in NH3 flow at 1350 °C for 4 h. Phases, chemical composition and microcosmic feature of cryomilled powders and as-prepared nanowires were tested by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), respectively. The results suggested that Eu was successfully introduced into Si lattice after the cryomilling process and then entered into the lattice of α-Si3N4 during the nitridation process. The as-synthesized Eu-doped α-Si3N4 nanowires had highly uniform dimension with 20~30 nm in diameter and ~100 μm in length. The room temperature photoluminescence (PL) spectrum of as-synthesized nanowires showed a broad band emission center at 570 nm which was attributed to the transition from 4f65d to 4f7 in Eu2+. The transition from Eu3+ to Eu2+ during nitridation process was tested by X-ray photoelectron spectroscopy (XPS).

Eu- and Tb-adsorbed Si3N4and Ge3N4: tuning the colours with one luminescent host

“…In most cases only Eu-and Tb-doped a-Si 3 N 4 thin lms and nanowires illustrating broad band emission are concerned. [33][34][35][36][37][38][39][40][41] Here we use the expression doping explicitly as this is given in the references.…”

“…This indicated that if some luminescence spectra may seem very similar overall at rst sight, it turns out that denitely some changes are observed. [33][34][35][36][37][38][39][40][41]…”