Absorption And Reflection Properties Of Azo Grating With Random Textured Surface In Thin Film Solar Cells

To discuss the effect of aluminum-doped zinc oxide (AZO)sine grating with a random rough surface on the absorption and reflectivity of thin film silicon solar cells. The random rough surface was expressed with Correlation length (Cor_ 1) and Average height (Ave_ h), and superimposed on the one-dimensional AZO sine grating with 980 nm period and 160 nm groove height. Random rough surface AZO gratings were used as the front electrode of thin film silicon solar cells with 1000 nm silicon absorption layer thickness. Theoretical simulation results showed that the influence of Cor_ 1 on the reflectivity was smaller than that of Ave_ h. Moreover, high specular reflection acquired in the range of Cor_ 1 0.011 similar to 0.015 and Ave_ h 0.2-0.8. When the Cor_ l was fixed, the diffuse reflection decreased with the increase of the Ave_ h. Results of the solar cell absorption showed that the thin film silicon solar cell with Ave_ h in the range of 0.2 similar to 0.8 had strong absorption at 440 similar to 500 nm, 575 similar to 710 nm, 740 similar to 755 nm and 795 similar to 815 nm wavelength band as the Cor_ 1 was 0.01. In the aspect of experiment fabrication, random rough surface AZO grating and smooth surface AZO grating was fabricated with wet etching and lift-off process respectively. It was suggested that as front electrode, random rough surface AZO grating with smaller Cor_ 1 and larger Ave_ h could suppress reflection and enhance absorption, so as to improve light trapping efficiency of the thin film silicon solar cells.