Усиление комбинационного рассеяния света в субволновых плазмонных наноструктурах, полученных методом ионно-лучевой литографии
Смирнов И. С., Мамичев Д., Андреев А. и др. Кристаллография. 2014. Т. 59. № 1. С. 137-144.
By using ion-beam lithography we have obtained subwavelength grating with optimized architecture corresponding to the spectral position of the resonances at desired wavelengths. Structural and optical properties of the obtained nanostructures were investigated. Signal intensity of Raman scattering from molecules of substances adsorbed on the surface gratings with optimized architecture increased to 10 000 times. These nanostructures can be used as a basis for the creation of highly sensitive sensors and a variety of optoelectronic components
Added: Feb 20, 2014
Ikhsanov R. Physica Status Solidi RRL. 2015. Vol. 9. No. 10. P. 570-574.
Transition absorption of a photon by an electron passing through a boundary between two media with different permittivities is described both classically and quantum mechanically. Transition absorption is shown to make a substantial contribution to photoelectron emission at a metal/semiconductor interface in nanoplasmonic systems, and is put forth as a possible microscopic mechanism of the surface photoelectric effect in photodetectors and solar cells containing plasmonic nanoparticles.
Added: Sep 27, 2015
Hot Electron Photoemission from Plasmonic Nanostructures: The Role of Surface Photoemission and Transition Absorption
Ikhsanov R., Babicheva V. E., Zhukovsky S. V. et al. ACS Photonics. 2015. Vol. 2. No. 8. P. 1039-1048.
We study mechanisms of photoemission of hot electrons from plasmonic nanoparticles. We analyze the contribution of “transition absorption”, i.e., loss of energy of electrons passing through the boundary between different materials, to the surface mechanism of photoemission. We calculate photoemission rate and transition absorption for nanoparticles surrounded by various media with a broad range of permittivities and show that photoemission rate and transition absorption follow the same dependence on the permittivity. Thus, we conclude that transition absorption is responsible for the enhancement of photoemission in the surface scenario. We calculate the ratio of photoemission cross-section for a gold nanosphere embedded in different materials such as silicon, zinc oxide, and titanium dioxide. For the calculations, we include both surface and bulk mechanisms of photoemission, using quantum calculations for the former one and a three-step phenomenological approach for the latter one. By comparison of both mechanisms, we show that the role of surface mechanism in the total photoemission cannot be neglected, as it dominates in the near-infrared wavelength range. We also show that in order to increase the photoemission rate, one benefits from placing nanoparticles in materials with lower permittivity. Finally, we apply our results to the case of nanowires partially embedded in a semiconductor substrate, which is a practically relevant design for narrow-band photodetection. Summarizing these results, we show that the reported narrow-band photoemission increase can at least partially be attributed to the surface mechanism.
Added: Sep 27, 2015