Brieler Felix J, Grundmann Petra, Fröba Michael, Chen Limei, Klar Peter J, Heimbrodt Wolfram, Krug von Nidda Hans-Albrecht, Kurz Thomas, Loidl Alois
Institute of Inorganic and Analytical Chemistry, Justus-Liebig University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen, Germany.
J Am Chem Soc. 2004 Jan 28;126(3):797-807. doi: 10.1021/ja038960j.
Arrays of highly ordered Zn(1-x)MnxS quantum wires with x ranging from 0.01 to 0.3 and with lateral dimensions of 3, 6, and 9 nm were synthesized within mesoporous SiO2 host structures of the MCM-41 and SBA-15 type. The hexagonal symmetry of these arrays (space group p6m) and the high degree of order was confirmed by X-ray diffraction and transmission electron microscopy (TEM) studies. Physisorption measurements show the progressive filling of the pores of the SiO2 host structures, while TEM and Raman studies reveal the wire-like character of the incorporated Zn(1-x)MnxS nanostructures. X-ray absorption near-edge structure, extended X-ray absorption fine structure, photoluminescence excitation (PLE), and electron paramagnetic resonance studies confirm the good crystalline quality of the incorporated Zn(1-x)MnxS guest species and, in particular, that the Mn2+ ions are randomly distributed and are situated on tetrahedrally coordinated cation sites of the Zn(1-x)MnxS wires for all x up to 0.3. The amount of Mn2+ ions loosely bound to the surface of the Zn(1-x)MnxS nanowires is less than 4% of the total Mn content even for the 3 nm nanostructures up to the highest Mn content of x = 0.3. The effects of the reduction of the lateral dimensions on electronic properties of the diluted magnetic semiconductor were studied by PLE spectroscopy. Due to the quantum confinement of the excitons in the wires an increase of the direct band gap with decreasing particle size is observed.
合成了高度有序的Zn(1-x)MnxS量子线阵列，其中x范围为0.01至0.3，横向尺寸为3、6和9纳米，这些量子线阵列生长在MCM-41和SBA-15型介孔SiO2主体结构内。通过X射线衍射和透射电子显微镜（TEM）研究证实了这些阵列的六方对称性（空间群p6m）和高度有序性。物理吸附测量表明SiO2主体结构的孔隙逐渐被填满，而TEM和拉曼研究揭示了掺入的Zn(1-x)MnxS纳米结构的线状特征。X射线吸收近边结构、扩展X射线吸收精细结构、光致发光激发（PLE）和电子顺磁共振研究证实了掺入的Zn(1-x)MnxS客体物种具有良好的晶体质量，特别是对于所有x直至0.3，Mn2+离子随机分布并位于Zn(1-x)MnxS量子线的四面体配位阳离子位点上。即使对于3纳米的纳米结构，直至最高Mn含量x = 0.3，松散结合在Zn(1-x)MnxS纳米线表面的Mn2+离子数量也不到总Mn含量的4%。通过PLE光谱研究了横向尺寸减小对稀磁半导体电子性质的影响。由于量子线中激子的量子限制，观察到随着粒径减小直接带隙增加。
