High-tech adhesives for thin-film solar cells

Thin-film solar cells are used for facades, lightweight roofs, or charging columns. They are made up of several layers with a thickness in the millimeter range. The active, energy-producing layers are often vapor-deposited onto glass or an organic carrier material and covered with protective film on the front and back.

An adhesive that can be used to reliably bond the protective film is DELO KATIOBOND LP655. The light-curing epoxy resin also acts as a barrier and effectively protects the active layers from humidity. This is particularly important at the edges, as penetrating humidity would impair the solar cells' functionality.

Thanks to the raw materials used, the adhesive has a low water vapor transmission rate of 6 g per mm/m² in 24 h, which has been tested at a temperature of +60 °C and a relative humidity of 90%. This prevents premature degradation of the solar cells and contributes to a long lifetime.

DELO KATIOBOND LP655 also features high peel resistance on PET, the plastic material typically used for protective films. The transparent adhesive cures in seconds under UV light and has been optimised for slot-die coating. Also for roll-to-roll processes DELO offers various products based on epoxy resins and acrylates.

DELO continues to develop adhesive solutions that are specifically adapted to the ever changing technical and economic requirements in the solar industry. The adhesives undergo intensive testing, conducted in cooperation with global development partners such as Oninn Innovation Center from Brazil. Furthermore, DELO offers adhesive solutions for other technologies in the field of renewable energies, including wind power or battery systems for electric cars, which, thanks to their multifunctionality, perform other tasks in addition to reliably bonding two components.