Inkjet printed silver back contacts for flexible amorphous silicon thin-film solar cells on glass fiber fabrics

The preparation of inkjet printed silver back contacts for flexible amorphous silicon thin-film solar cells on textile glass fiber fabrics is presented. The silver tracks were printed onto glass fiber fabrics that are stabilized with a polymer. The thermal expansion coefficient of the polymer is approximately 450 times higher than that of silver. To prepare the solar cell structure the following deposition steps (active material and top electrode) require temperatures of maximum 170. Therefore, the main challenge was to avoid a cracking inside the silver layers since otherwise the functionality of the whole device will be destroyed by shunting due to shortcuts. By combining different low-temperature sintering techniques and therefore developing a special sintering routine, it was possible to produce smooth silver layers which are highly resistant against tensile and compressive stress and therefore can withstand the temperature cycling of the following deposition steps without cracking.