Castro Rene, Spivak Yulia, Shevchenko Sergey, Moshnikov Vyacheslav
Department of Physical Electronics, Faculty of Physics, Herzen State Pedagogical University of Russia (Herzen University), 191186 Saint Petersburg, Russia.
Department of Micro- and Nanoelectronics, Faculty of Electronics, Saint Petersburg Electrotechnical University «LETI», 197376 Saint Petersburg, Russia.
Materials (Basel). 2021 May 11;14(10):2471. doi: 10.3390/ma14102471.
The spectra of dielectric relaxation of macroporous silicon with a mesoporous skin layer in the frequency range 1-10 Hz during cooling (up to 293-173 K) and heating (293-333 K) are presented. Macroporous silicon (pore diameter ≈ 2.2-2.7 μm) with a meso-macroporous skin layer was obtained by the method of electrochemical anodic dissolution of monocrystalline silicon in a Unno-Imai cell. A mesoporous skin layer with a thickness of about 100-200 nm in the form of cone-shaped nanostructures with pore diameters near 13-25 nm and sizes of skeletal part about 35-40 nm by ion-electron microscopy was observed. The temperature dependence of the relaxation of the most probable relaxation time is characterized by two linear sections with different slope values; the change in the slope character is observed at T ≈ 250 K. The features of the distribution of relaxation times in meso-macroporous silicon at temperatures of 223, 273, and 293 K are revealed. The Havriliak-Negami approach was used for approximation of the relaxation curves ″ = (ν). The existence of a symmetric distribution of relaxers for all temperatures was found (Cole-Cole model). A discussion of results is provided, taking into account the structure of the studied object.
给出了具有介孔表层的大孔硅在冷却（至293 - 173K）和加热（293 - 333K）过程中1 - 10Hz频率范围内的介电弛豫谱。通过在Unno - Imai池中对单晶硅进行电化学阳极溶解的方法获得了具有介观大孔表层的大孔硅（孔径约2.2 - 2.7μm）。通过离子电子显微镜观察到，介孔表层厚度约为100 - 200nm，呈锥形纳米结构形式，孔径接近13 - 25nm，骨架部分尺寸约为35 - 40nm。最可能弛豫时间的弛豫温度依赖性由两个具有不同斜率值的线性部分表征；在T≈250K时观察到斜率特征的变化。揭示了介观大孔硅在223、273和293K温度下弛豫时间分布的特征。采用Havriliak - Negami方法对弛豫曲线″ = (ν)进行拟合。发现所有温度下弛豫剂均存在对称分布（Cole - Cole模型）。结合研究对象的结构对结果进行了讨论。
