硫系化合物
纳米晶
材料科学
成核
量子点
纳米技术
发光
红外线的
化学工程
光电子学
化学
光学
有机化学
工程类
物理
作者
Maksym Yarema,Stefan Pichler,Mykhailo Sytnyk,Robert Seyrkammer,R. T. Lechner,Gerhard Fritz,Dorota Jarzab,Krisztina Szendrei,Roland Resel,Oleksandra Korovyanko,Maria Antonietta Loi,Oskar Paris,Günter Hesser,Wolfgang Heiß
出处
期刊:ACS Nano
[American Chemical Society]
日期:2011-04-18
卷期号:5 (5): 3758-3765
被引量:182
摘要
Here, we present a hot injection synthesis of colloidal Ag chalcogenide nanocrystals (Ag2Se, Ag2Te, and Ag2S) that resulted in exceptionally small nanocrystal sizes in the range between 2 and 4 nm. Ag chalcogenide nanocrystals exhibit band gap energies within the near-infrared spectral region, making these materials promising as environmentally benign alternatives to established infrared active nanocrystals containing toxic metals such as Hg, Cd, and Pb. We present Ag2Se nanocrystals in detail, giving size-tunable luminescence with quantum yields above 1.7%. The luminescence, with a decay time on the order of 130 ns, was shown to improve due to the growth of a monolayer thick ZnSe shell. Photoconductivity with a quantum efficiency of 27% was achieved by blending the Ag2Se nanocrystals with a soluble fullerene derivative. The co-injection of lithium silylamide was found to be crucial to the synthesis of Ag chalcogenide nanocrystals, which drastically increased their nucleation rate even at relatively low growth temperatures. Because the same observation was made for the nucleation of Cd chalcogenide nanocrystals, we conclude that the addition of lithium silylamide might generally promote wet-chemical synthesis of metal chalcogenide nanocrystals, including in as-yet unexplored materials.
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