Market-Driven EFG Modules, Annual Subcontract Report, 14 December 1996 - 13 February 1998

Technical Report · Tue Dec 15 00:00:00 EST 1998

DOI:https://doi.org/10.2172/6903· OSTI ID:6903

Kardauskas, M; Kalejs, J ^[1]

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1. ASE Americas, Inc., Billerica, Massachusetts

This report summarizes the progress made at ASE Americas Inc. during Phase II of this subcontract. Accomplishments under Task 4: Wafers include optimization of edge-defined film-fed growth (EFG) crystal growth variables, leading to reduced crystal stresses and improved wafer flatness; increased die run length due to improvements in the design of furnace components; construction and testing of EFG growth furnace enclosure; reduction of EFG wafer thickness from 300 {micro}m for 50% of all standard production material; implementation of new equipment to reduce costs of silicon feedstock sorting prior to EFG crystal growth with a 3% increase in silicon feedstock utilization; and development work demonstrating the laser cutting of EFG wafers at higher speeds and with reduced silicon damage. Accomplishments under Task 5: Cells include characterization of cells after diffusion as preliminary work toward improving diffusion conditions and improving cell efficiency; demonstration of a continuous process to remove phosphorus glass from diffused wafers, reducing chemical consumption and hazardous waste by 98%; development of statistical process control methods to improve cell production process control; the use of design of experiments to study interactions between processing at various steps in cell manufacturing, and to develop strategies for productivity improvements; improvements in EFG cell efficiency due to the reduction in average wafer thickness; design and construction of equipment for producing cells with an improved grid design; and demonstration of average efficiencies over 14.1% on production lots of EFG cells. Accomplishments under Task 6: Modules include production and successful testing of prototypes of a lower-cost module diode housing; successful demonstration of a module design that greatly improves collection of light from space between cells in modules; testing of new encapsulants and lamination processes to demonstrate reduced lamination time, improved yield and enhanced durability; and completion of options study for lower-cost module frames, and development of a frameless module design using mounting clamps.

• 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: 6903
• Report Number(s): NREL/SR-520-25817; TRN: US200307%%170
• Resource Relation: Other Information: Supercedes report DE00006903; PBD: 15 Dec 1998; PBD: 15 Dec 1998
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
CRYSTAL GROWTH
DESIGN
DIFFUSION
EFFICIENCY
FURNACES
OPTIMIZATION
PHOSPHORUS
PROCESS CONTROL
SILICON
SORTING
STRESSES
TESTING
THICKNESS
WASTES
PHOTOVOLTAICS
PHOTOVOLTAIC MANUFACTURING TECHNOLOGY
PVMAT
EDGE-DEFINED FILM-FED GROWTH
EFG
SILICON WAFERS
WAFER MANUFACTURING
CELL MANUFACTURING
MODULE MANUFACTURING