Research On The Radiative Properties Of Gratings As Absorbers For Solar Cells

It is a promising direction to develop photovoltaic industry for its clean and renewablecharacteristics. Solar cell is the core of the photovoltaic industry, which faces two bigproblems: high cost and low efficiency. Surface microstructures can be used as light-trappingstructure for solar cells to improve the efficiency. This thesis does researches and analysis ofone-dimensional (1D) and two-dimensional (2D) silicon gratings as absorbers for solar cellsto enhance absorption of sunlight in the visible and near-infrared wavelength regions.A study is carried out to evaluate the influences of different structural parameters on theabsorptance of1D simple gratings based on the rigorous coupled-wave analysis (RCWA)method. The associated absorptance peaks of1D simple gratings are narrowband anddirection sensitive. In order to remedy the above drawbacks of1D simple gratings, two kindsof1D complex concave gratings are proposed. The RCWA method is adopted for researcheson the spectral and directional radiative properties of1D complex concave gratings, and theTaguchi method is used to search the optimal profiles. The results show that the associatedabsorptance peaks for1D complex gratings are boarder band and less direction sensitive than1D simple gratings for TM wave，but the absorptive properties of1D complex concavegratings are unsatisfactory for TE wave.One kind of2D complex convex grating and two kinds of2D complex concave gratingsare proposed for a potential application as absorbing surfaces for solar cells. The finite-difference time-domain (FDTD) method is adopted for researches on the spectral anddirectional radiative properties of2D complex gratings, and the Taguchi method is used tosearch the optimal profiles. The results show that the2D complex gratings can achievesatisfactory performance for both TM and TE waves. Therefore, the gratings proposed in thisthesis can be well suitable for solar absorber applications.