Polyperinaphthalene and Carbon Thin Films Prepared by Direct Laser Writing of 3,4,9,10-Perylene Tetracarboxylic Acid: Processing, Structure, and Electrical and Thermoelectric Property Investigation

By leveraging the limited solubility of 3,4,9,10-perylene tetracarboxylic acid (PTCA) in dimethyl sulfoxide, we develop a direct laser writing (DLW) process for fabricating the narrow-bandgap conducting polymer–polyperinaphthalene (PPN) as well as carbon thin films under 1 μm thickness. The effects of CO 2 laser power and precursor thickness on the structure, morphology, and electrical/thermoelectric properties of the resultant DLW products are investigated. The compounding role of laser power and precursor thickness on PPN-to-carbon transition is revealed. Under the optimal processing conditions, the resultant DLW film achieves excellent electrical conductivity of 120 S·cm –1 with a Seebeck coefficient of 8.5 μV·K –1 and a power factor of 0.96 μW·m –1 ·K –2 . Last, the PTCA-derived DLW thin film is demonstrated for self-powered sensing applications in laser power monitoring and as a flexible, wearable thermoelectric sensor for temperature sensing. The present study paves a way for low-cost fabricating high-performance PPN and carbon thin films that may offer a versatile platform for a wide range of applications.