To maximise the degree of light incoupling, therefore improving the short circuit current and efficiency of solar cells, a novel subwavelength (SW) structured 'moth-eye' antireflection coating (ARC) is formed on the sun-facing side of the glass superstrate. This moth-eye structure in theory can suppress reflection entirely in the 300-1200 nm wavelength range. It is produced by fabricating a mask, followed by reactive ion etch. In this paper, we present a novel etch mask, a random Ag nanoparticle array on glass with feature size ranging from ∼50 nm to ∼350 nm. The subwavelength features can be adjusted by varying the size, shape and distribution of the Ag nanoparticle array, which in turn is tuned by varying as-deposited Ag thickness. The optimal structures reduce reflection loss by a current equivalent of 1.25 mA/cm2 for a 3.3 mm borosilicate glass (BSG) superstrate, by 1.39 mA/cm2 for 1.1 mm BSG and enhances Jsc by 3.4% on average for 2.4 μm poly-Si thin-film solar cells on 3.3 mm BSG. On Si film side of the glass surface, a preliminary modulated texture investigation, consisting of growing SW structure on micron sized aluminium induced textured (AIT) glass reduced reflection loss by ∼7% compared to original AIT samples.
- subwavelength structure
- broadband antireflection coating
- Ag nanoparticles
- solar cells