Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 2017 | public
Book Section - Chapter

Enhanced Light Trapping in Thin Silicon Solar Cells using Effectively Transparent Contacts (ETCs)


We report on the light trapping properties of densely spaced microscale triangular cross-section effectively transparent contacts (ETCs). Optical simulations of thin silicon with closely spaced ETCs were performed and the absorption within the silicon was determined. We found that with a metal coverage of 62.5% the short circuit current density would only be decreased by 0.25%. Such low value of parasitic reflection and transmission is obtained due to the excellent reflection properties of silver microstructures. In the interval 700 nm-1100 nm the short circuit current density is even enhanced by around 1 mA/cm2 compared to a structure without any metal contact. This results from nearly loss free in-coupling in combination with internal reflection at the bottom of the metal lines which increases the path length of light. These results are particularly interesting for 4-terminal silicon tandem devices as the bottom cell only receives the spectrum between around 850 nm and 1100 nm.

Additional Information

© 2017 IEEE. The authors thank Thomas Russell for helpful discussion. This material was based upon work supported by the U.S. Department of Energy through the Bay Area Photovoltaic Consortium under Award Number DE-EE0004946 and by the Engineering Research Center Program of the National Science Foundation and the Office of Energy Efficiency and Renewable Energy of the Department of Energy under NSF Cooperative Agreement No. EEC-1041895.

Additional details

August 19, 2023
October 19, 2023