Advanced Light Trapping of High-Efficiency Thin Film Silicon Solar Cells

Kaneka has been proposing and developing the "advanced super-light trapping (ASLT)" structure for thin film silicon solar cells, which incorporates tailored light confinement structures in tandem thin film silicon solar cells to selectively enhance light trapping in top and bottom subcells. In this paper, we present the results of the development of intermediate reflectors with very low refractive index and the design and implementation of nanoimprinted substrates. We demonstrate that significant current gains are possible by reducing the refractive index of the interlayer beyond state-of-the-art values. In addition, we show that the transparent conductive oxide angular scattering properties correlate with the solar cell performance in the infrared part of the spectrum.