Granitzer Petra, Rumpf Klemens, Poelt Peter, Reissner Michael
Institute of Physics, University of Graz, Graz, Austria.
Institute for Electron Microscopy, University of Technology Graz, Graz, Austria.
Front Chem. 2019 Jan 29;7:41. doi: 10.3389/fchem.2019.00041. eCollection 2019.
The aim of the presented work is to combine luminescent porous silicon (PSi) with a ferromagnetic metal (Ni) to modify on the one hand the photoluminescence by the presence of metal deposits and on the other hand to influence the optical properties by an external magnetic field. The optical properties are investigated especially with respect to the wavelength-shift of the photoluminescence due to the metal filling. With increasing metal deposits within PSi the photoluminescence peak is blue-shifted and furthermore an increase of the intensity is observed. Photoluminescence spectra of bare PSi show a maximum around 620 nm whereas in the case of Ni filled samples the peak is blue-shifted to around 580 nm for a deposition time of 15 min. Field dependent magnetic measurements performed with an applied field parallel and perpendicular to the surface, respectively, show a magnetic anisotropy which is in agreement with a thin film. This film-like behavior is caused by the interconnected Ni structures due to the branched porous silicon morphology. The coercivity increases with increasing metal deposition from about 150 Oe to about 450 Oe and also the magnetic anisotropy is enhanced with the growth of metal deposits. Within this work the influence of the magnetic metal filling on the optical properties and the magnetic characterization of the nanocomposites are discussed. The presented systems give not only rise to optoelectronics applications but also to magneto optical integrated devices.
本文工作的目的是将发光多孔硅（PSi）与铁磁金属（Ni）相结合，一方面通过金属沉积物的存在来改变光致发光，另一方面通过外部磁场影响光学性质。特别研究了由于金属填充导致的光致发光波长偏移的光学性质。随着PSi中金属沉积物的增加，光致发光峰发生蓝移，并且还观察到强度增加。裸PSi的光致发光光谱在620nm左右显示出最大值，而对于Ni填充的样品，在沉积时间为15分钟时，峰蓝移至580nm左右。分别在与表面平行和垂直的外加磁场下进行的场依赖磁性测量显示出与薄膜一致的磁各向异性。这种薄膜状行为是由分支多孔硅形态导致的相互连接的Ni结构引起的。矫顽力随着金属沉积量的增加从约150 Oe增加到约450 Oe，并且磁各向异性也随着金属沉积物的生长而增强。在这项工作中，讨论了磁性金属填充对纳米复合材料光学性质和磁性表征的影响。所提出的系统不仅促进了光电子学应用，还促进了磁光集成器件的发展。
