Performance and reliability of silicone polymers in 1000X concentration CPV applications

Abstract

Establishing the performance and reliability of silicone polymers in 1000X CPV applications is critical to producing a reliable product as well as assuring customer confidence. Silicones are robust materials, but the CPV application environment is especially severe and silicone performance under such conditions has not been well documented. Targeted testing of silicone polymers is one technique to rapidly establish and compare the performance of these materials under highly stressed conditions. The targeted testing described in this work consisted of single variable stress tests in which one relevant stress was maximized and combined effects stress tests where the samples experienced stress more representative of field conditions. Optical transmission of the bulk silicone polymer decreased significantly within 50 hours at 175°C with the UV and visible portions of the spectrum experiencing the largest changes. Optical transmission of the bulk silicone polymer did not change upon exposure to 350nm UV light at room temperature. Combined effects tests of several silicone polymers on-sun have shown that elimination of the UV portion of the solar spectrum greatly enhances silicone lifetime. © 2012 American Institute of Physics.