Spectral control of near-field radiation transfer from Metal-Insulator-Metal (MIM) structured emitter made of Ni and SiO2 to Metal-Semiconductor-Metal (MSM) structured Thermo-photovoltaic (TPV) cell made of GaSb semiconductor and Au is studied using Finite Difference Time Domain (FDTD) method. As the simulation result, enhancement of near-field thermal radiation flux is observed among near infrared radiation range for GaSb TPV cell, 1.0~1.6μm, mainly by the structure of MIM emitter. In addition, inside of GaSb is partially stimulated by MIM emitter and MSM structures.
Spectral control of near-field radiation transfer by interference of Surface Plasmon Polaritons (SPPs) in pillar array structured surface made of nickel was investigated using a numerical simulation based on Maxwell’s electromagnetic wave theory. The electromagnetic field between two pillar array structured surfaces fixed in face to face with a vacuum gap of several hundred nanometers was obtained using a three dimensional Finite Difference Time Domain (FDTD) method and fluctuational electrodynamics (FED). The near-field radiation flux from a high temperature to a low temperature pillar array structured surfaces was evaluated through the summation of normal components of Poynting vector in any direction at the intermediate of the vacuum gap. Through the numerical simulation, it was clarified that the local maximum and the local minimum of near-field radiation flux were shown periodically with increasing height of pillar under the condition of a fixed vacuum gap, which was regarded as interference between the pillar height and an electromagnetic wave propagating in the channel between pillars. Moreover, the dispersion relation of the electromagnetic wave with interference in the channel between pillars is quite similar to the SPPs established in two semi-infinite smooth plates with a nanometer vacuum gap. As a result, it was concluded that the spectral control of near-field radiation transfer was achieved by interference of SPPs in the channel between pillars by tuning the height of pillar.
It is well known that damage and fracture of the structure are originated from slipping and breaking binds between atomics, which could emit manifold physical signals. Thus, the detection of those signals will bring us a lot of information as linking between micro and macro structure. Many studies in this area have been focused on detection of physical signals generated by fracture phenomenon. On the other hand, the signal by dislocation, which could be related to plastic deformation, has never been interested. The dislocation could disturb an electric density field in crystal structure. It is thus expected that the disturbed field forms an electric dipole. Consequently, when the dislocation is moved rapidly, electromagnetic wave will be radiated from this dipole. In this study, electric density field around an edge dislocation is analyzed using first-principles calculation. As a result, it was confirmed that the existence of the dipole was identified around the dislocation core, and an electromagnetic radiation from the dislocation movement was estimated.
There are many studies for detecting several physical signals generated by fracture phenomenon. However, the signal by dislocation motion, which is related to plastic deformation, has never been interested. The dislocation could disturb an electric density field in crystal structure. It is expected that the disturbed field forms an electric dipole. When the dislocation is moved rapidly, electromagnetic wave will be radiated from this dipole. In this study, electric density field around an edge dislocation is analyzed based on a first-principles calculation. Influence of different strain, atomic number Z and dislocation movement on the dipole was also discussed. As a result, the magnitude of dipole was varied with strain and was linearly increased as the atomic number Z. Moreover, electromagnetic radiation from the dislocation movement was estimated.