High Efficiency Thin Film Silicon Hybrid Cell and Module with Newly Developed Innovative Interlayer

Abstract

The paper discusses the development of a new light trapping scheme for a thin film Si based stacked cell and module, where a newly developed innovative interlayer is inserted between amorphous and microcrystalline Si thin film. This new interlayer leads intentional controlling of the refractive index of it. The interlayer with a lower refractive index of 1.7 at 600 nm exhibits both better reflection towards the top amorphous silicon cell and less absorption loss towards the bottom microcrystalline cell. We also proved by numerical simulation that the effect of the interlayer on light trapping towards the top cell is more enhanced with textured substrate. An initial cell efficiency of 15.0% has been achieved in a small area (1cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) of its cell with this new interlayer. An initial aperture efficiency of 13.4% has been achieved for a 910times455 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> Si HYBRID PLUS module fabricated in a single chamber process of p-i-n microcrystalline cell, which was independently confirmed by AIST