Elit Process: Epitaxial Layers for Interdigitated Back Contacts Solar Cells Transferred

A novel approach for the silicon thin-film solar cells transfer technology was developed at INSA-LYON, named ELIT process (Epitaxial Layers for Interdigitated back contacts solar cells Transferred using porous silicon). In this paper, all the process steps are described. Starting from the formation of a double porous silicon layer on the whole substrate surface, a high crystal quality Si layer is grown by Vapor Phase Epitaxy. This single crystal epitaxial layer is then processed into solar cells by realizing all the contacts on the back side. Finally, these rear contacts solar cells are transferred onto a glass plate and separated from the initial Si substrate before TMAH texturation and deposition of PECVD SiN antireflective coating on the front side. Interdigitated Back Contacts solar cells (BC) with an efficiency of 7.7% and 8.2% were achieved.