Silicon-Film(TM) Solar Cells by a Flexible Manufacturing System: PVMaT Phase II Annual Report, 1 February 1999 - 31 January 2000

AstroPower is developing a manufacturing process for Silicon-Film(TM) solar cell production under an NREL-administered Photovoltaic Manufacturing Technology (PVMaT) cost-share program. This document reports on results from the second phase of a three-phase effort. Progress is reported on the development of new procedures and equipment for in-line wet chemical processes, sheet fabrication, solarcell processing, and module assembly. Future concepts and goals for the Silicon-Film(TM) process are also discussed. A major technical goal of this effort is the elimination of batch production processes in AstroPower's solar cell process. New processes are being developed that can accommodate large-area Silicon-Film(TM) planks in an in-line, continuous manner. During Phase II of this program,an in-line chemical etching system for removing diffusion oxides was specified, procured, and installed. Operation of this system during Phase III of this program is expected to validate the in-line approach and will provide valuable information for use in the design of a second, and more challenging, in-line etch system. Significant progress was made during this reporting period in thedevelopment of new screenprinting ink formulations for both the front and back metallization of Silicon-Film(TM) solar cells. Cost reductions and efficiency improvements were achieved as a result of these efforts. Progress was made in the design of a new Silicon-Film(TM) plank machine, as well as in improved processes to fabricate this material into cost-effective and efficient solar cells.Additionally, a new large-area module concept was developed and prototyped during this phase of the PVMaT program.