Synthesis and photoluminescence of heavily La-doped 伪-Si₃N₄ nanowires via nitriding cyromilled nanocrystalline La-doped silicon powder

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• 作者：Zhihao Wang^a ; Zhifeng Huang^a ; Fei Chen^a ; ^b ; ^{chenfei027@gmail.com" class="auth_mail} ; Qiang Shen^a ; Lianmeng Zhang^a ; ^b
• 关键词：Silicon nitride nanowire ; Lanthanum ; CASTEP program ; Photoluminescence
• 刊名：Journal of Luminescence
• 出版年：July, 2014
• 年：2014
• 卷：151
• 期：Complete
• 页码：66-70
• 全文大小：2577 K

文摘

In this paper, the synthesis of heavily La-doped 伪-Si₃N₄ nanowires is firstly reported via nitriding the cryomilled La-doped nanocrystalline Si powder. The crystal structure, electronic structure and band structure of La-doped 伪-Si₃N₄ are calculated by using the CASTEP program code based on the first principles plane-wave pseudo-potential method. The microstructure and photoluminescence of heavily La-doped 伪-Si₃N₄ nanowires are investigated. The results suggest that La has been already incorporated into Si lattice after the cryomilling process and then successfully entered the lattice of 伪-Si₃N₄ with the nitridation process. The as-synthesized heavily La-doped 伪-Si₃N₄ nanowires show high purity and good crystallinity with 30-40 nm in diameter and several tens of micrometers in length. The optical property shows that there is an intense violet-blue visible emission from 350 nm to 450 nm with one peak at 388 nm due to the recombination between the valence band and the N₄⁺ level at room temperature, which is in agreement with the calculated band structure of La-doped 伪-Si₃N₄.