Study Of Solar Energy Absorption Properties Of Subwavelength Structure Materials

In this paper,a hexagonal array is proposed,which is numerically simulated by using the FDTD method in wide-band,wide-angle and different polarization modes.For a single cycle,there is only a single microstructure to improve.Select the optimal parameters of the cone and cylindrical composite structure as a structural unit,the arrangement of internal and external cycles,the internal cycle of the hexagonal arrangement of the bottom of the radius R and the cell spacing d are further studied by numerical simulation.The following conclusions can be drawn:(1)The reflection characteristics of silicon substrate,monolayer,multilayer,one-dimensional subwavelength grating and two-dimensional subwavelength grating are investigated.At the specific wavelength and the specific incident angle,the monolayer film has better anti-reflection effect than the silicon substrate.The multilayer film overcomes the shortcomings of the monolayer film and achieves good anti-counteraction effect in wide band and wide angle,but the manufacturing process is complicated and costly.One-dimensional subwavelength gratings has low manufacturing cost and good anti-reflection effect,but One-dimensional subwavelength grating is sensitive to polarization mode and it appears birefringence.The two-dimensional sub-wavelength grating is symmetrical,it overcomes the sensitivity and birefringence of the one-dimensional subwavelength grating for different polarization modes,it has good anti-reflection effect.(2)For the microstructure with gradient cross-section,the reflectivity decreases first and then increases with the increase of the total height of the structural unit.The reflectivity decreases first and then increases with the height of the bottom cylinder.The reflectivity decreases when the ratio of the bottom diameter to the period increases(3)For different arrangement of polygons,the arrangement of pentagons in the odd-numbered arrangement is better than the triangular arrangement.Even arrangement of the hexagonal arrangement of the structure has good anti-reflection effect than the quadrilateral arrangement.The structure of evennumbered arrays is better than that of odd-numbered ones,and the structure of hexagonal arrangement has the best antireflective effect.The hexagonal arrangement of the inner periodic structure is better than the outer periodic structure in comparison with the hexagonal arrangement of inner and outer cycles.For the hexagonal arrangement of the inner periodic structure,the reflectivity decreases first and then increases with the radius of the bottom.For the spacing of the structural units,the reflectivity decreases first and then increases with the increase of the cell spacing.(4)The best structure is the combination of cylinder and cone and it is arranged in the hexagonal arrangement of the inner structure.The total height of the structure is 600 nm,the height of the column is 100 nm,the radius of the bottom is 150 nm,and the spacing is 340 nm.The calculated results show that this structure exhibits a good antireflective effect with a minimum average reflectance of less than 1% at a wide incident angle of 0 °-60 ° and a different polarization mode in the 400nm-2500 nm band.