Study On Thermal Radiation Properties Of Metal Micro-nano Plasmonic Structures

Local surface plasma resonance(LSPR)results in strong light-matter interaction and the concentrates incident radiation onto localized volumes around the nanoparticles(NPs)generated locally enhanced electromagnetic field.Light trapping and electromagnetic field concentrating properties of the localized surface plasmon(LSP)attract great interest and open up a wide range of applications.Especially,as the most important applications,the plasmon photothermal and thermal radiation applications have a great potential in important technological areas such as solar photothermal conversion,solar desalination,infrared sensing,photothermal therapy,radiation cooling and thermal management,which are systematically studied.To improve the above applications,enormous amount of efforts contribute valuable insights on the plasmon-induced photo-field and photothermal enhancement mechanism to enhance the photothermal conversion.For example,the heat sources in the plasma structure plotted by experiments and numerical methods.In addition,for the research of thermal radiation,lots of work focus on mapping the radiation produced at the sample surface,the thermal radiation controlled by nanoscale structure,radiative cooling and thermal transfer,and so on.The thermal radiation Scanning tunneling microscope image of thermal excitation surface plasma are demonstrated for the first time by experimental method,and the spatial coherence effect of near-field thermal radiation is proved,which proves the macroscopic and tunable thermal transmitter in the experiment.In addition,a large number of studies based on Kirchhoff's law have discussed the relationship between thermal emission spectra and material components through optical absorption spectroscopy.The results show that the thermal radiation spectrum can be adjusting by changing the structure or material composition.In fact,the relationship between photothermal properties and thermal radiation characteristics is highly correlated,which is important for photothermal and thermal radiation applications.However,there is little work to consider the thermal radiation generated by photothermal,which will cool the temperature of the plasma and limit the further enhancement of photothermal conversion.What's more,there is little work to study the thermal radiation characteristics of plasma surface or interior by numerical method in order to explore the photothermal radiation mechanism of plasma structure further.In this paper,the photothermal generation and thermal radiation properties in plasma structure are simulating and studying by combining the principles of optics,thermodynamics and thermal radiation,and the specific research work is as follows:(1)Several micro/nano-plasma structures of NP_qp,NP_s and NP_e were constructed and simulated.In T<333 K,compared with the black body radiation of these plasma nanostructures,the photothermal conversion of solar energy in the thermal radiation spectrum is consistent with that in low temperature applications.Compared with the thermal radiation spectra of these plasma structures,it is finding that thermal radiation is obviously relating to its structure,and through the morphological changes of micro/nano-plasma.The peak position and relative strength of the thermal radiation spectrum change dramatically,which indicates that the thermal radiation characteristics are relating to its morphology.By changing the size of the NP_qps,the thermal radiation peak in the thermal radiation spectrum moves,indicating that the structural parameters of the thermal radiation material are correlating with its thermal radiation performance.Finally,by comparing the maximum radiation peak strength of the three and the numerical simulation of the thermal radiation distribution of the plasma structure,it is finding that the high thermal radiation originates from the NP_qp bottom area with the tip and sharp edges,which indicates that the sharper end can produce stronger thermal radiation.(2)A micro/nano-plasma component NP_se has been constructing,and its calculation and simulation are carrying out.It is observing that the thermal radiation spectrum can detect the movement of the peak shift of thermal radiation.The maximum radiation peak strength of the NP_se is the strongest in the control of the maximum radiation peak intensity of the single NP_s,NP_e and the combined NP_se.Then by changing the morphology or reasonable combination of the plasma structure,the thermal radiation characteristics of this plasma can be effectively adjusting.From the rectangular area in the thermal emission map,it can be finding that the tip and adjacent resonant areas show stronger thermal emission than the middle section of the NP_e,suggesting that adjacent coupling enhances thermal emission and that the coupled tip thermal emission is more intensive.Moreover,this work combines the numerical simulation results of photoluminescence and thermal radiation,which provide guidance for the design of effective photothermal,thermal radiation materials and the regulation of thermal radiation properties.