Maskless digital manufacturing of organic thin film transistor by femtosecond laser direct patterning

The small volume, large variety item manufacturing has been recognized as a next generation manufacturing scheme to satisfy the various demands from the customers. As a promising manufacturing technique, laser based maskless digital patterning emerged recently. Especially, the fabrication of metal nanopatterns on various substrates, such as glass and flexible polymers, has become important for various electronic device applications. In this study, we used the direct femtosecond laser sintering of metal nanocrystals to fabricate organic thin-film transistors. This process is an ultra-high-resolution direct metal patterning method in which the metal nanocrystals are sintered with a femtosecond laser beam to form high quality metal electrodes for the bottom gated organic thin film transistors with pentacene as an active layer. Organic thin-film transistors with PFBT treatments were demonstrated showing good performance with the mobility up to 0.0173 cm²/Vs. These results indicate that the femtosecond laser sintering of metal nanocrystals can be applied to numerous applications in electronics.