Surface passivation by L-arginine and enhanced optical properties of CdS quantum dots co-doped with Nd3+-Li+
Surface passivation by L-arginine and enhanced optical properties of CdS quantum dots co-doped with Nd3+-Li+
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DOI：
10.1007/s40097-015-0151-4
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发表时间：
2015-06-01
影响因子：
10.1
通讯作者：
Muley, G. G.
中科院分区：
文献类型：
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作者：
Talwatkar, S. S.;Sunatkari, A. L.;Muley, G. G.
采用化学沉淀法合成了L-精氨酸钝化的Nd 3+和Li+共掺杂的CdS量子点（QD）。制备的量子点的紫外-可见吸收光谱显示在477-450 nm范围内的吸收，表明由于量子限制效应，与体CdS相比，能带隙发生了巨大的蓝移。当掺杂浓度从1增加到5wt%时，光学带隙从2.44增加到2.97 eV。光致发光光谱表明，共掺杂的CdS量子点是高度发光的，并发射多个强烈的紫色（362，371，385，395 nm）和蓝色（422，445，456和465 nm）的彩色峰，随着共掺杂剂浓度的增加强度。傅立叶变换红外光谱研究证实了CdS纳米粒子与L-精氨酸配体之间的相互作用。结构和形貌研究表明，形成了正交晶体结构。CdS量子点的大小，通过X射线衍射和高分辨率透射电子显微镜分析，发现减少与共掺杂剂浓度。能量色散X射线分析显示除了掺杂剂之外不存在杂质，表明所制备的样品的高纯度。根据这些结果，我们认为该材料是一类适合于光电子器件应用的新型发光材料，特别是在发光器件、电致发光器件和显示器件中的应用。
L-Arginine-passivated Nd3+ and Li+ co-doped CdS quantum dots (QDs) were synthesized by chemical precipitation method. Ultraviolet-visible absorption spectra of prepared QDs show absorption in the range of 477-450 nm indicating huge blue shift in energy band gap as compared to the bulk CdS due to quantum confinement effect. The optical band gap is found increasing from 2.44 to 2.97 eV as the doping concentration increased from 1 to 5 wt%. Photoluminescence spectra showed that co-doped CdS QDs are highly luminescent and emit multiple intense violet (362, 371, 385, 395 nm) and blue (422, 445, 456 and 465 nm) coloured peaks with increasing intensity with co-dopant concentration. Fourier transform infrared study confirmed the interaction between CdS nanoparticles and L-arginine ligands. The structural and morphological study revealed the formation of orthorhombic crystal structure. The size of CdS QDs, as analysed by X-ray diffraction and high-resolution transmission electron microscopy, is found reducing with co-dopant concentration. The energy dispersive X-ray analysis shows no impurities present except dopants indicating high purity of the prepared samples. Based on the results, we proposed that this material is a new class of luminescent material suitable for optoelectronics devices' application, especially in light emitting devices, electroluminescent devices and display devices.