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Title: Laser-zone growth in a Ribbon-to-Ribbon (RTR) process. Silicon Sheet Growth Development for the Large Area Silicon Sheet Task of the Low Cost Silicon Solar Array Project. Technical quarterly report No. 5. Motorola report No. 2256/6

Technical Report ·
DOI:https://doi.org/10.2172/5253148· OSTI ID:5253148

The objective of this research is to fully investigate the Ribbon-to-Ribbon (RTR) approach to silicon ribbon growth. An existing RTR apparatus, RTR No. 1, is to be upgraded to allow for 5 cm wide ribbon growth with a finite stroke length of at least 15 cm. A second RTR apparatus, RTR No. 2, is to be designed, built, and operated which is to utilize continuous feed mechanisms and which will ultimately allow continuous growth of 7.5 cm wide ribbons. RTR No. 2 is also to include development and utilization of advanced beam scanning (or shaping), high power lasers, and thermal profile modification elements to attain maximum growth velocities (with a design goal of 18 cm/min). Materials studies, process development, and thermal analyses are also major elements of this research. Residual stresses and dislocation densities are to be minimized through theoretical and experimental efforts towards optimization of thermal profiles. Material analysis and process development are to be performed with a goal of demonstration of solar cell efficiencies greater than 12%. Efforts to date have centered on design and initiation of construction of RTR No. 2 and upgrading of RTR No. 1. Growth runs have been performed on RTR No. 2 and solar cells have been fabricated which have demonstrated efficiencies greater than 10%.

Research Organization:
Motorola, Inc., Phoenix, Ariz. (USA). Semiconductor Group
DOE Contract Number:
NAS-7-100-954376
OSTI ID:
5253148
Report Number(s):
ERDA/JPL/954376-77/3
Country of Publication:
United States
Language:
English