Title:	Si Wafer Manufacturing by Thermal Spray of Recycled Si Powders
Author(s):	M. Vardavoulias, A.S. Azar, T. Halvorsen, M. Moen, K. Mork, P.A. Carvalho, O. Dahl, A. Ulyashin
Keywords:	c-Si, Thin Film (TF), Silicon, Films, Substrates, Thermal Spray
Topic:	Silicon Photovoltaics
Subtopic:	Feedstock, Crystallisation, Wafering, Defect Engineering
Event:	33rd European Photovoltaic Solar Energy Conference and Exhibition
Session:	2AV.1.18
Pages:	509 - 512
ISBN:	3-936338-47-7
Paper DOI:	10.4229/EUPVSEC20172017-2AV.1.18
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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The aim of the present work is to demonstrate processing of polycrystalline free-standing Si wafers and thin Si layers on various substrates using thermal spray of relevant Si powders, including recycled ones. Silicon powders were fabricated by milling from two different Si feedstocks: (i) Si kerf produced during sawing of Si wafers from the ingots, and (ii) Si powder from Si scrap (broken wafers). Two different Si powder based structures were produced by thermal spray: (i) free-standing Si-based wafers with thicknesses of about 300-400 micrometres and sizes up to 6 inches, which can be used as supporting parts for "Si wafer equivalent" structures, and, (ii) Si-based layers with thicknesses of about 50-100 micrometres deposited on different supporting substrates, such as aluminium, glass and highly conductive Si powder based sintered substrates. Raman spectroscopy, resistivity, and SEM analyses have been used for characterization of the Si based structures fabricated by thermal spray. It is observed that such layers are poly-crystalline with a low-fraction of the amorphous phase and can be considered as a low-cost alternative for Si PV, which are based on utilization of Si wafers and thin Si layers deposited by conventional methods such as CVD, PECVD, e-beam, etc.