Using light-induced thermocleavage in a roll-to-roll process for polymer solar cells

We report on the use of intense visible light with a narrow spectral distribution matched to the region where the conjugated polymer material absorbs to selectively heat the active material and induce thermocleavage. We show a full roll-to-roll process, leading to complete large-area polymer solar cell modules using light-induced thermocleavage. The process employs full solution processing in air for all five layers in the device and does not employ indium?tin oxide or vacuum processing. The process steps were carefully analyzed using X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, attenuated total reflectance infrared, and transmission/reflection UVvis techniques.