Multi-chromatic silicon nanocrystals

• 来源期刊: 光：科学与应用（英文版）
• 关键词: cathodoluminscence color center electron beam multi-chromaticity silicon nanocrystals
• 年，卷（期）: 2017,（3）
• 页码范围: 40-48
• 页数: 9页
• 语种: 英文
• DOI: 10.1038/Isa.2017.7

摘要

Silicon nanocrystals (SiNCs) have great potential to become environmental friendly alternatives to heavy-metal containing nano-crystals for applications including medical imaging,lighting and displays.SiNCs exhibit excellent photostability,non-toxicity and abundant resources,but their often reported inefficient and spectrally limited light emission seriously impair their applications.Here we demonstrate a new method that converts SiNCs into an efficient and robust multi-chromatic phosphor.Using ～ 15 keV electron-beam irradiation of oxide-capped SiNCs,we introduce several types of color centers into the nanocrystal's oxide shell with efficient blue,green and red emission bands,together yielding warm-white photoluminescence,even for a single SiNC.Introduced centers are not native to the original system and we relate them to known defects in silica.Unlike in the silica host,however,here the centers are efficiently optically excitable.Provided further optimization and up-scaling of this method,e-beam irradiated SiNCs can be of great interest as white phosphors for applications such as LEDs.