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Information × Registration Number 0223U004874, 0123U102712 , R & D reports Title Computer design, synthesis and heat transfer properties of silicon nanostructures for energy efficient applications popup.stage_title Head Kuryliuk Vasyl V., Кандидат фізико-математичних наук Registration Date 06-12-2023 Organization Taras Shevchenko National University of Kyiv popup.description2 Objects: Silicon nanostructures with various morphologies. Research Objective: Establishing the physical peculiarities of heat transport in low-dimensional semiconductor structures for application in the field of thermal management of modern micro-, nano-, and optoelectronic components, as well as efficient harvesting of electrical voltage in thermoelectric systems. Research Methods: Electrochemical etching, scanning electron microscopy, infrared spectroscopy, reflectance spectroscopy, photoacoustic technique, molecular dynamics method. Using the molecular dynamics method, temperature dependencies of the thermal conductivity coefficient of silicon and silicon nanowires of various morphologies were calculated. Phonon characteristics (density of phonon states, phonon dispersion curves, frequency dependencies of phonon velocity and relaxation time) of Si nanowires of various morphologies were analyzed. It was demonstrated that the reduction in thermal conductivity of rough nanowires is a result of the decrease in phonon velocity and lifetime due to scattering on the developed surface of rough nanowires. Multilayer structures of porous Si were synthesized by the electrochemical etching method. Anodization of silicon in a periodic mode with short current interruptions allowed the creation of uniformly deep structures of arbitrary thickness. Using scanning electron microscopy and reflectance spectroscopy, it was shown that a multilayer porous silicon with sharp planar interfaces between the layers was obtained. Calculations of the deformation, thermal, and radiation effects on the thermal conductivity of Si nanostructures were provided. It was demonstrated that the thermal conductivity change in nanowires and porous nanostructures is associated with a reduction in the phonon relaxation time, accompanied by a decrease in the propagation velocity of acoustic vibrational modes. Product Description popup.authors Dubyk Kateryna V. Lishchuk Pavlo O. Popyuk Catherine V. Semchuk Svyatoslav S. Chornyi Roman V. Shevchenko Viktoriya В. popup.nrat_date 2023-12-06 Close