Femtosecond laser writing of PPV-doped three-dimensional polymeric microstructures

Poly(para-phenylene vinylene) (PPV) is a key material for optoelectronics because it combines the potential of both polymers and semiconductors. PPV has been synthesized via solution-processable precursor route, in which the precursor polymer poly(xylene tetrahydrothiophenium chloride) (PTHT) is thermally converted to PPV throughout the sample as a whole. Much effort has been devoted to fulfill spatial selectivity of PPV conversion. However, none of the methods proposed stand for PPV conversion three dimensionally, which would be appealing for the design of microdevices. Here, we demonstrate the potential of fs-laser direct writing via two-photon polymerization (2PP) to fabricate PPV-doped 3D microstructures. PTHT is incorporated into the polymeric material and it is subsequently converted to PPV through a thermal treatment. Optical measurements, taken prior and after thermal conversion, confirm the PTHT to PPV conversion. Fs-laser direct writing via 2PP can be exploited to fabricate a variety of 3D microdevices, thus opening new avenues in polymer-based optoelectronics. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 479-483