High-tech adhesives for thin-film solar cells offer protection against humidity

DELO offers adhesives for solar cells for the first time. The light-curing products based on epoxy resins or acrylates are ideal for bonding the protective films of thin-film solar cells while simultaneously creating an effective barrier against humidity.

Thin-film solar cells are employed for facades, lightweight roofs, or charging columns. They are constructed of several layers with a thickness in the millimetre range. The active, energy-producing layers are frequently vapour-deposited onto glass or organic carrier material and sheathed with protective film on the front and back.

DELO KATIOBOND LP655 is an adhesive that can reliably bond protective film. The light-curing epoxy resin also performs as a barrier and protects the active layers from humidity. This is especially important at the edges, as penetrating humidity can impair the solar cells' functionality. Thanks to the raw materials employed, the adhesive has a low water vapour transmission rate of 6g per mm/m² in 24h, which has been tested at a temperature of +60C and relative humidity of 90%. This stops premature degradation of the solar cells and contributes to a long lifetime.

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