The light trapping glass operates using simple optical principles and is wavelength- and absorber- independent, which makes it compatible with all types of solar cells, including wafer-based and thin films. In addition, it can be used for both metal grid and TCO based module architectures.
The research team of Lucent Optics has conducted proof-of-concept studies of the light trapping PV technology which included both modeling and component-level prototyping. In the “ideal” approximation, light path enhancement factors of over 1,000X were obtained. The results obtained for realistic models of the PV module with conservative design limitations have shown broad-band light path enhancements factors up to 200X compared to the bare Si wafer. Such dramatic enhancement in the light path length yields a potential of 6-7 times reduction in Si reflectance and over a hundred times improvement in light absorption in the IR spectrum.
The graph on the left shows the anticipated impact of employing the proposed technology on c-Si PV cell performance. The black line shows short circuit density versus cell thickness for a bare cell (no light trapping). The blue line corresponds to the same cell having state-of-the-art random pyramid texture. The green line indicates the theoretical limit of light trapping with substrate texturing. The red line (on top) corresponds to the case of bare wafer covered with the light trapping glass.