The EU Project R2M-Si on Roll to Module Processed Crystalline Silicon Thin-Films

Abstract

This paper presents a summary of the EU project “roll to module processed crystalline silicon thinfilms” (R2M-Si). The aim of this project was to lift off c-Si-thin-films in a cost effective manner, and to process them to integrated interconnected solar cells. One major goal was therefore to provide Si foil material for solar cells with a high efficiency potential. Within the R2M-Si project both the theoretical understanding and the actual process development of porosifying and detaching layers from flat wafers as well as from the circumference of a silicon rod have been investigated. Studies on crystal orientation dependence of the porosification along with tool development towards a continuous formation of a separation layer were accompanied by in depth understanding and thus optimization of the reorganization and subsequent epitaxial growth process. Finally the introduction of a special attachment process and an integrated solar cell concept could be achieved.