Standard for Silicon Wafer for Use in PV Solar Cells Published
By Kevin Nguyen, SEMI Standards
SEMI PV22-1011 Specification for Silicon Wafers for Use in Photovoltaic Solar Cells was recently published in October 2011. This standard replaces SEMI M6-1108 Specification for Silicon Wafers for Use as Photovoltaic Solar Cells, which does not reflect current commercial practice in the crystalline silicon photovoltaic (PV) industry. A ballot will be submitted to make SEMI M6 obsolete early next year.
PV22 provides standardized dimensional and other numerous characteristics of silicon wafers based on currently widely used sizes for 100, 125, 156, and 210 mm for PV applications. Covering both single crystalline and multi-crystalline silicon, this standard encompasses dimensions for pseudo-square and square wafers.
Ordering wafers can be a challenge since there are extensive elements associated with wafer properties such as electrical, chemical, crystal, and defect characteristics. How would one tailor a wafer ordering sheet? Using this specification, user can provide supplier a systematic basis for constructing the purchase order for any kind of crystalline silicon wafers for PV applications. In addition, user may also select test methodology for verifying wafer characteristics.
When asked, “Describe how this standard will provide cost savings or overall economic benefit?” Dr. Murray Bullis, the author, explains, “A basic material specification always provides cost savings to the industry by standardizing the starting materials for various systems.” He also adds, “This specification provides reference to common test methods that are used between the materials supplier and its customers. Use of such test methods is extremely valuable to the industry by avoiding discrepancies between parties in regard to selection of tests and meeting of specification requirements.” It is a win-win scenario for both user and supplier when PV22 is utilized.
PV22 gains industry’s acceptance after several round of stringent ballot processes. The standard achieved true consensus with input from worldwide members. If you feel this standard can be improved, revision may be suggested by contacting your local SEMI Standards staff.
SEMI Standards Watch, December 2011