Maskless laser direct patterning of PEDOT/PSS layer for soluble process organic thin film transistor

In this work, we have fabricated TIPS-pentacene TFTs with conductive polymer (3,4-ethylenedioxythiophene):poly(4-stylenesulfonate) (PEDOT:PSS) source/drain electrodes which is patterned by maskless laser direct patterning (LDP). The 5-microm resolution of source and drain patterns with PEDOT:PSS were clearly defined. Furthermore, the OTFTs with 10-microm channel length were successfully achieved by exposing the focused Neodymium:Yttrium Aluminum Garnet (Nd:YAG) laser beam onto the spin-coated PEDOT:PSS films and developing with deionized water. The electrical performance of the TIPS-pentacene TFTs with PEDOT:PSS source/drain electrodes were improved with decrease of the sheet resistance of PEDOT:PSS films when the PEDOT:PSS films were annealed at the temperature above 200 degrees C.