SunPower Announces Discovery of Surface Polarization Effect
SUNNYVALE, Calif., August 22, 2005 - SunPower Corp., a Silicon Valley-based subsidiary of Cypress Semiconductor Corp. (NYSE: CY), today announced the discovery of a new performance effect observed in high efficiency silicon solar cells. This new effect, called “surface polarization,” creates the non-destructive and reversible accumulation of static charge on the surface of high-efficiency solar cells such as the company’s all-back-contact A-300.
Surface polarization occurs when minute amounts of electrical current leak through the face of the solar cell and accumulate on the surface. Current leakage of this sort is present in all solar systems but will accumulate or dissipate on the solar cells’ surface depending on system grounding polarity and configuration. The presence or absence of surface charge can decrease or increase solar cell current generation in a fashion analogous to the switching of a programmable memory transistor.
SunPower found that electricity production in systems using high-efficiency solar cells could be significantly decreased or increased by varying the system wiring and grounding configurations, and that these performance changes were relatively rapid and completely reversible. As the result of their discovery, SunPower scientists have developed and applied for patents on new solar cell and system designs that eliminate surface polarization.
Dick Swanson, SunPower’s founder and CTO, noted, “We believe that the surface polarization effect will be seen in many types of high-efficiency crystalline solar cells. We are pleased that our research and development team discovered and characterized surface polarization and subsequently developed practical measures to eliminate this effect in real-world PV system configurations.”
SunPower-a Silicon Valley-based majority-owned subsidiary of Cypress Semiconductor Corp. ( NYSE: CY )-designs and manufactures high-performance silicon solar cells and panels based on an all-back-contact design. SunPower’s solar cells and panels generate up to 50 percent more power per square foot than similarly sized conventional solar technologies and have an attractive, all-black appearance. For more information on SunPower or solar technology, please visit the SunPower website at http://www.sunpowercorp.com.
Cypress solutions are at the heart of any system that is built to perform: consumer, computation, data communications, automotive, industrial, and solar power. Leveraging a strong commitment to customer service and performance-based process and manufacturing expertise, Cypress’s product portfolio includes a broad selection of wired and wireless USB devices, CMOS image sensors, timing solutions, network search engines, specialty memories, high-bandwidth synchronous and micropower memory products, optical solutions, and reconfigurable mixed-signal arrays. Cypress stock is traded on the New York Stock Exchange under the ticker symbol CY. More information about the company is available online at www.cypress.com.