Structure Design And Study On Surface Plasmon Resonance Based Solar Energy Absorbers

The increasing demand for energy and environmental issues force people to explore renewable energy.Solar energy is currently the focus of research on renewable energy due to its clean,pollution-free,and abundant resources.Solar energy absorbers are the core components for the collection and utilization of solar energy.Surface plasmon resonance can break the traditional optical diffraction limit and has a strong electromagnetic field enhancement effect.Solar energy absorbers based on surface plasmon resonance can achieve efficient and ultra broadband absorption,and are currently a hot research topic in solar energy absorbers.This thesis introduced the research background,mechanism and application of surface plasmon resonance.The finite difference time domain method is used to simulate the designed solar energy absorber,analyze its optical performance.The specific research content is as follows:（1）A broadband solar energy absorber based on Ti-Al₂O₃cross elliptical disk array was proposed.The structure achieved an average absorption of 98.78%at the wavelength from 385 nm to 1765 nm.At the solar energy radiation region of 280 nm to 2600 nm,the average absorption is 98.4%.The physical mechanism of efficient absorption was analyzed through the distribution of electric and magnetic fields.The geometric parameters of designed structure were optimized.The overall thickness of this structure is only 445 nm,and it still maintains high absorption when changing the polarization direction and incidence angle of the incident light.It has value in solar energy utilization.（2）A rectangular staggered multilayer thin film stack structure solar absorber was designed,which composed of TiO₂-SiO₂-Ti N rectangular array and TiO₂-SiO₂-Ti thin films.This structure has a broadband absorption above 90%in the 376 nm to 5156 nm wavelength range,with average of 95.91%.This structure not only achieves an energy absorption of 95.65%in the region of solar energy radiation,but also has a thermal emission efficiency of 95.85%at a temperature of 1500K.The distribution of electric and magnetic field intensity reveals the physical mechanism of broadband absorption,and the absorption spectrum we need is tuned by changing its geometric parameters.The broadband absorption performance and thermal emission efficiency make it has potential value in energy absorption and emission applications.