Photoconductivity of Composites Based on Polymer P3ht and Silicon Nanoparticles / Aleksandr Pavlikov, Konsantin Savin, Pavel Forsh, Dmitrij Amasev, Andrej Kazanskij, Aleksej Tameev

Секция 4. Формирование наноматериалов и наноструктур = Section 4. Formation of Nanomaterials and NanostructuresСформированы нитевидные наноструктуры германия методом катодного осаждения из водных растворов оксида германия. Осаждение производилось на титановую фольгу, в качестве центров роста использовались наночастицы индия. Полученные наноструктуры исследовались методами электронной микроскопии, комбинационного рассеяния света (КРС) и инфракрасной (ИК) спектроскопии. Изображения, полученные с помощью растрового электронного микроскопа, показали, что образуются нитевидные наноструктуры, а при плотности тока 0.5 мА/см2 также образуется сплошной слой, что согласуется с данными ИК спектроскопии. На основании данных КРС установлено, что полученные нитевидные наноструктуры являются нанонитями аморфного германия. Облучение наноструктур гелий-неоновым лазером интенсивностью более 30 Вт/см2 приводит к локальному нагреву и последующей локальной кристаллизации облученных областей.Работа выполнена при финансовой поддержке грантов РФФИ № 18-29-23005 и 18-02-01103.The nanostructured layers of germanium are formed by the method of cathodic deposition from aqueous solutions of germanium oxide. Deposition was performed on titanium foil, and indium nanoparticles were used as growth centers. The obtained nanostructures were studied by electron microscopy, Raman scattering and infrared (IR) spectroscopy. According to scanning electron microscopy layers of nanowires with thickness of about 100 nm were formed. The sample formed at a current density of 0.5 mA /cm2 had a solid layer. This layer was well observed on SEM images, and the the presence of this layer is consistent with IR spectroscopic data. Raman spectroscopy revealed that the obtained nanowires are amorphous germanium nanowires. This follows from the detected spectral band at 280 cm-1, characteristic of a-Ge. This band was detected in the Raman spectra with the minimum power of the exciting laser radiation. Irradiation of nanostructures with a He-Ne laser with an intensity of more than 30 W /cm2 leads to local heating and subsequent local crystallization of the irradiated areas. An additional confirmation of the local heating hypothesis was the study of the ratio of the Stokes to the anti-Stokes component. These results indicate that the region irradiated by the exciting laser is heated to a temperature of about 1000 K. This effect may be explained by low thermal conductivity of the layers. The IR reflectance spectra displayed the absence of any absorption lines characteristic of other compounds. The observed difference in the reflection coefficients is explained by the presence of the solid layer between the nanowires and the substrate consisting of Ge. The presence of a solid layer leads to an increase in the effective refractive index, which in turn increases the scattering of radiation by the rough surface of the layer. Therefore, the reflection coefficient for the sample with solid layer does not exceed 30%.The other samples are practically transparent for IR radiation in the range from 400 to 1000 cm-1, and the reflection coefficient exceeds 80%. In the region of larger wavenumbers, scattering processes play an important role, since the radiation wavelength becomes comparable with the size of inhomogeneities of the surface of the Ge layer of nanostructures. Thus, we obtained layers of amorphous Ge nanowires with low thermal conductivity. These layers may be easily crystallized by visible radiation of low intensity