Numerical Study On Thermal Radiative Properties Of One-dimensional Complex Gratings

The tuning of the spectral and directional radiation properties can be applied in manyapplications, such as thermal imaging, solar thermal and solar cells. Electromagneticradiation from micro-structured surface, however, usually divides into differentwavelengths and angles, which makes the research urgent. Among all the microstructures,1-D gratings are widely used for their good performance and easy fabrication. This thesisconsiders the1-D gratings radiation properties with the help of FDTD method and thegrating anomalies phenomena. We give the detailed description of our work as follows,Firstly, we discussed the radiation properties of p-doped silicon and silicon kind of1-D simple gratings with the help of FDTD method and the grating anomalies phenomena.By considering the p-doped silicon gratings, we find that Microcavity resonance has bettertotal spectrum tuning performance than SPPs. Then, we consider the effect of differentkinds of parameters on the thermal radiation properties of silicon gratings, and find thatsimple gratings can only tune the narrow band radiation properties. To improve the totalspectrum of radiation properties, we introduce the concept of complex gratings. Byanalyzing the radiation properties of complex gratings, we find that the radiation propertiesof complex gratings is both broad-band and direction-insensitive. Then we compare theradiation properties of complex gratings with2and3grooves, and find that the2-groovegratings have the advantages of easy fabrication, broad-band and symmetric obliqueincidence. Thus,2-groove grating is suit for solar cell applications.