ROLE OF ANTIREFLECTION COATING IN MICROGROOVED SILICON SOLAR-CELLS

The role of AR coatings in microgrooved solar cells having different s lat angles has been studied in detail deriving the expression of the r eflection coefficient for various slat angles for unencapsulated and e ncapsulated cells. The role of flats of texturized surfaces have also been studied. It is shown that there is little influence of the AR coa ting when the slat angle is less than 55 degrees, while the improvemen t of the short-circuit current may be as high as 22% on a slat angle o f 70.5 degrees, It is observed that encapsulated cells having small gr oove angles (< 55 degrees) have greater efficiencies than the cells ha ving groove angles in the range of 90 degrees to 120 degrees, but exhi bit larger variation in efficiency with changes in the flat-top area c overage. The optimum thickness for single layer AR coated (ZnS) encaps ulated cells and also for SiO2 coated unencapsulated cells is 1250 Ang strom.