Silicon foil solar cells on low cost supports

In this work, we report recent results of solar cells fabricated on silicon foils obtained by the Stress induced LIft-off Method (SLIM)-cut technique using an epoxy stress-inducing layer. Indeed, the use of silicon foils for the production of solar cells offers the ability to reduce material costs while allowing potentially a higher conversion efficiency. We show experimentally that silicon foil thicknesses between 40 and 140 mu m can be tuned by changing the thickness of the epoxy. Standalone silicon foil based solar cells have been realized, and conversion efficiencies of 12.5% and 13.8% have been measured using 55 mu m and 120 mu m thick foils, respectively. In view of potential industrialization, mechanical support must be used during solar cells and module fabrication to avoid silicon foil breakage. Two different supporting substrates were therefore tested: an aluminum sheet and a sintered silicon substrate. Conversion efficiencies of 10.9% and 12.1% were obtained using 40 mu m and 90 mu m thick silicon foils on a polished Al substrate. Finally, a promising result of 13.1% was obtained after mini-module fabrication from 6 SLIM-cut solar cells (100 mu m thick silicon foils) on the sintered silicon substrate using the i-cell concept. Published by AIP Publishing.