Process research on polycrystalline-silicon material (PROPSM). Quarterly report, January 1, 1983-March 31, 1983

Technical Report · Sat Jan 01 04:00:00 EST 1983

DOI:https://doi.org/10.2172/6282797· OSTI ID:6282797

Culik, J. S.

The investigation of the performance-limiting mechanisms in large-grain (greater than 1 to 2 mm in diameter) polycrystalline silicon was continued by fabricating a set of mini-cell wafers on a selection of 10cm x 10 cm wafers. A mini-cell wafer consists of an array of small (approximately 0.2cm/sup 2/ in area) photodiodes which are isolated from one another by a mesa structure. The mini-cell wafer set is composed of: (1) three wafers from Semix brick 71-01E near the bottom, in the middle, and near the top; (2) two wafers from Semix bricks C4-108 and C4-116B; (3) a Wacker silso wafer; and (4) a single-crystal Czochralski wafer as a control. The conjunction capacitance of each mini-cell was used to obtain the dopant concentration, and therefore the resistivity, as a function of position across each wafer. The results indicate that there is no significant variation in resistivity with position for any of the polycrystalline wafers, whether Semix or Wacker, howeever, the resistivity of Semix brick 71-01E did decrease slightly from bottom to top. The shunt conductance of each mini-cell was used to locate areas on each wafer where the effects of a resistive shunt on any additional electrical measurements can be ignored. The results show that each wafer has areas of contiguous mini-cells in which the values of shunt conductane are less than that which would affect the open-circuit voltage or the fill-factor. However, the dimensions and the location of these low conductance areas vary from wafer-to-wafer and with position in the brick. An effort was begun to investigate the usefulness of a high-temperature heat treatment in order to getter possible minority-carrier lifetime-killing impurities from the bulk.

• Research Organization: Solarex Corp., Rockville, MD (USA)
• DOE Contract Number: NAS-7-100-955902
• OSTI ID: 6282797
• Report Number(s): DOE/JPL/955902-83/9; ON: DE83012702
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
CAPACITANCE
CRYSTALS
DIRECT ENERGY CONVERTERS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRIC POTENTIAL
ELECTRICAL PROPERTIES
EQUIPMENT
FABRICATION
FILL FACTORS
GETTERING
IMPURITIES
MATERIALS
PERFORMANCE
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
POLYCRYSTALS
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT