Microplasma synthesis of tunable photoluminescent silicon nanocrystals
Microplasma synthesis of tunable photoluminescent silicon nanocrystals
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DOI：
10.1088/0957-4484/18/23/235603
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发表时间：
2007-06-13
期刊：
影响因子：
3.5
通讯作者：
Okazaki, Ken
中科院分区：
文献类型：
--
作者：
Nozaki, Tomohiro;Sasaki, Kenji;Okazaki, Ken
开发了一种常压微等离子体反应器，用于制造可调谐光致发光硅纳米晶体。氩气、氢气和四氯化硅的混合物被体积小于1μl的毛细玻璃管中产生的电容耦合非平衡等离子体激活。尽管停留时间约为100μs，微等离子体仍能有效地将四氯化硅分解成原子硅。然后，过饱和硅蒸气通过三体碰撞导致气相晶体成核，随后由于反应器停留时间短而快速终止晶体生长。硅纳米晶是在室温下气相连续合成的。氢浓度约为0.7-0.8%的合成材料的室温光致发光（PL）表现出强烈的可见光发射，峰值强度集中在670 nm附近。随着氢含量的增加，PL光谱蓝移至520 nm，这意味着合成了直径小于3 nm的部分氧化的纳米晶体。
An atmospheric-pressure microplasma reactor was developed for the fabrication of tunable photoluminescent silicon nanocrystals. A mixture of argon, hydrogen, and silicon tetrachloride was activated by a capacitively coupled non-equilibrium plasma generated in a capillary glass tube with a volume less than 1 mu l. The microplasma efficiently decomposes silicon tetrachloride into atomic silicon even though the residence time is approximately 100 mu s. Supersaturated silicon vapour then leads to gas phase crystal nucleation via three-body collision, followed by rapid termination of crystal growth due to the short reactor residence time. Silicon nanocrystals are continuously synthesized in gas phase at room temperature. The room-temperature photoluminescence ( PL) of as-synthesized material with hydrogen concentration around 0.7-0.8% exhibited intense visible light emission with peak intensity centred around 670 nm. The PL spectrum was blue-shifted to 520 nm with increasing hydrogen content, implying that partially oxidized nanocrystals of diameter less than 3 nm were synthesized.