Progress on crystalline silicon thin film solar cells by FBR-CVD: Effect of substrates and reactor design

• Main Authors: Perez-Mariano, J., Leung, T., Moro, L., Gleixner, S., Kai Lau, Chavez, B., Hornbostel, M., Sanjurjo, A.
• Format: Conference Proceeding
• Language: English
• Subjects: Impurities; Inductors; Photovoltaic cells; Silicon; Substrates; Surface treatment
• ISSN: 0160-8371
• DOI: 10.1109/PVSC.2011.6186592

Thin film polycrystalline solar cells on low cost substrates offer an attractive path to large scale production of solar cells with the potential to generate electricity at 1/W. SRI International has a propriety technology to deposit Si films in a reactor based on fluidized bed technology. The results presented in this paper show that, with a proper reactor design, Si films can be grown at rates of 7 μm/min and higher. Films are crystalline, with crystallite sizes higher than 20 μm. We have also evaluated the performance of SiO 2 diffusion barriers as a potential way towards the use of low cost substrates, such as metallurgical grade Si. Whereas SiO 2 layers of 0.1 μm are not sufficient to stop P diffusion from the substrate to the film, 0.7 μm layers are thick enough to accomplish this goal. The reactor configuration can be used for continuous and integrated cell/panel fabrication. At present we are building a first continuous reactor, and in this paper we present some preliminary considerations.