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Title: PVMaT cost reductions in the EFG high volume PV manufacturing line: Annual report, 5 August 1998--4 August 1999[PhotoVoltaic Manufacturing Technology, Edge-defined Film-fed Growth]

Technical Report ·
DOI:https://doi.org/10.2172/753785· OSTI ID:753785

This report describes work performed by ASE Americas researchers during the first year of this Photovoltaic Manufacturing Technology 5A2 program. Significant accomplishments in each of three task are as follows. Task 1--Manufacturing Systems: Researchers completed key node analysis, started statistical process control (SPC) charting, carried out design-of-experiment (DoE) matrices on the cell line to optimize efficiencies, performed a capacity and bottleneck study, prepared a baseline chemical waste analysis report, and completed writing of more than 50% of documentation and statistical sections of ISO 9000 procedures. A highlight of this task is that cell efficiencies in manufacturing were increased by 0.4%--0.5% absolute, to an average in excess of 14.2%, with the help of DoE and SPC methods. Task 2--Low-Cost Processes: Researchers designed, constructed, and tested a 50-cm-diameter, edge-defined, film-fed growth (EFG) cylinder crystal growth system to successfully produce thin cylinders up to 1.2 meters in length; completed a model for heat transfer; successfully deployed new nozzle designs and used them with a laser wafer-cutting system with the potential to decrease cutting labor costs by 75% and capital costs by 2X; achieved laser-cutting speeds of up to 8X and evaluation of this system is proceeding in production; identified laser-cutting conditions that reduce damage for both Q-switched Nd:YAG and copper-vapor lasers with the help of a breakthrough in fundamental understanding of cutting with these short-pulse-length lasers; and found that bulk EFG material lifetimes are optimized when co-firing of silicon nitride and aluminum is carried out with rapid thermal processing (RTP). Task 3--Flexible Manufacturing: Researchers improved large-volume manufacturing of 10-cm {times} 15-cm EFG wafers by developing laser-cutting fixtures, adapting carriers and fabricating adjustable racks for etching and rinsing facilities, and installing a high-speed data collection net work; initiated fracture studies to develop methods to reduce wafer breakage; and started a module field studies program to collect data on field failures to help identify potential manufacturing problems. New encapsulants, which cure at room temperature, are being tested to improve flexibility and provide higher yields for thin wafers in lamination.

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:
753785
Report Number(s):
NREL/SR-520-27478; TRN: AH200011%%5
Resource Relation:
Other Information: PBD: 16 Nov 1999
Country of Publication:
United States
Language:
English