Growth of silicon sheets from metallurgical-grade silicon
Abstract
Direct conversion of metallurgical grade silicon and Direct Arc Reactor (DAR) silicon into sheet form has been carried out using the Edge-Supported Pulling (ESP) technique. The 7 mm meniscus height associated with ESP permits the growth of 5 cm wide sheets, and the thermal stability provided by the edge filaments makes this method relatively insensitive to disruption by surface instability. Resistivities for metallurgical grade silicon sheets are 0.5-0.23 ohm-cm, and for DAR are 0.10-0.23 ohm-cm. Constitutional supercooling occurred under some growth conditions with both materials, and was sometimes severe enough to cause difficulties, particularly with metallurgical grade silicon. A tendency for higher impurity levels at grain boundaries than within grains was observed. The impurity and structural analysis of the material, and the electrical characteristics of solar cells made from metallurgical silicon sheets are also covered.
- Publication:
-
15th Photovoltaic Specialists Conference
- Pub Date:
- 1981
- Bibcode:
- 1981pvsp.conf..581C
- Keywords:
-
- Energy Conversion Efficiency;
- Impurities;
- Melts (Crystal Growth);
- Silicon;
- Solar Cells;
- Electrical Resistivity;
- Energy Technology;
- Flat Plates;
- Menisci;
- Microphotographs;
- Microstructure;
- Research And Development;
- Solar Energy Conversion;
- Surface Properties;
- Engineering (General)