NuSil Technology LLC, a manufacturer of silicone materials for the solar, photonics, electronics and aerospace industries, has launched two clear silicone adhesives for solar module assemblies.  These adhesives are suitable for applications subject to harsh environments, such as high-power LEDs or satellites, and are ideal for both concentrator photovoltaics and flat-panel designs.
Most optically clear silicone adhesives contain phenyl, which may cause yellowing when exposed to heat and UV light.  NuSil’s LS-6941 and LS-6140 adhesives are phenyl-free, so they provide the radiation resistance required by solar module assemblies.  Both adhesives have a Type A durometer of approximately 50 and refractive indices that range between 1.40-1.41 at 589nm. For easy processing, these materials can be cured at low temperatures or accelerated with heat. They stick well to glass and aluminum substrates, and primers to improve adhesion.
LS-6941 is a robust, optically clear, low-viscosity adhesive. Available in a two-part 10:1 mix ratio, LS-6941 is solvent-free and maintains good physical properties and electrical stability across a broad range of temperatures. Applications include protection against shock, vibration, moisture, UV, dust, chemicals and other environmental hazards.
LS-6140 is a low outgassing adhesive for applications requiring minimal volatile condensables. Offering heat and radiation resistance, LS-6140 is an optical elastomer based on a methyl-silicone polymer. With a low viscosity and a 1:1 mix ratio, this adhesive is also great for dispensing.
Nusil Solar