A Silicon Ingot Lifetime Tester for Industrial Use
- National Renewable Energy Laboratory
- Siemens Solar Industries, Camarillo, California
- Siemens Solar Industries, Vancouver, Washington
A specially designed lifetime measurement instrument has been developed to characterize silicon ingots before they are subjected to expensive slicing and solar-cell processing, thereby saving needless processing costs of inferior materials in a solar-cell production line. The instrument uses the direct-current photoconductance decay (DC-PCD) method for linear detection of the transient photoconductance signal and localized probing / illumination for necessary sensitivity on low resistivity and large samples. The instrument also has a compact and high-power laser diode as the light source, data averaging capability, a pneumatic ingot transport and probe positioning mechanism, and a user-friendly graphical interface for data acquisition / lifetime calculation / data storage / hardcopy for factory-floor use with quick turnaround. A 3-dimensional finite-element analysis indicates that the as-cut surface finish is adequate for measuring the bulk lifetime on the order of 50 ms or less. Measurement repeatability and clear distinction among different grades of feedstock materials have been demonstrated.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC36-83CH10093
- OSTI ID:
- 7130
- Report Number(s):
- NREL/CP-590-25681; ON: DE00007130; TRN: US200306%%287
- Resource Relation:
- Conference: Presented at the National Center for Photovoltaics Program Review Meeting, Denver, CO (US), 09/08/1998--09/11/1998; Other Information: PBD: 22 Oct 1998
- Country of Publication:
- United States
- Language:
- English
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