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Title: Continuous, Automated Manufacturing of String Ribbon Si PV Modules: Final Report, 21 May 1998 - 20 May 2001

Technical Report ·
DOI:https://doi.org/10.2172/786354· OSTI ID:786354

This report summarizes the work done under a three-year PVMaT Phase 5A2 program. The overall goal was to attain a continuous, highly automated, fully integrated PV production line. In crystal growth, advances were made that resulted in lower substrate costs, higher yields, and lower capital and labor costs. A new string material was developed and implemented. Following this development, better control of the edge meniscus was achieved. A completely new furnace design was accomplished, and this became the standard platform in our new factory. Automation included ribbon thickness control and laser cutting of String Ribbon strips. Characterization of Evergreen's String Ribbon silicon was done with extensive help from the NREL laboratories, and this work provided a foundation for higher efficiency cells in the future. Advances in cell manufacturing included the development of high-speed printing and drying methods for Evergreen's unique cell making method and the design and building of a completely automated cell line from the beginning of front-contact application to the final tabbing of the cells. A so-called no-etch process whereby substrates from crystal growth go directly into p-n junction formation and emerge from this sequence without needing to go in and out of plastic carriers for any wet-chemical processing was developed. Process development as well as automation were brought to bear on improvements in soldering technology and cell interconnection in general. Using state-of-the-art manufacturing science, the Fraunhofer USA Center for Manufacturing Innovation at Boston University facilitated layout and process flow for the operation of our new factory. Evergreen Solar's new factory began operations in the second quarter of 2001. A good measure of the significant impact of this PVMaT subcontract is that virtually all of the manufacturing developments stemming from this project have been incorporated in this new factory.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
AC36-99GO10337
OSTI ID:
786354
Report Number(s):
NREL/SR-520-30622; TRN: AH200136%%89
Resource Relation:
Other Information: PBD: 1 Aug 2001
Country of Publication:
United States
Language:
English