Photoelectrochemical Polymerization (PEP) of EDOT for Formation of Pattered PEDOT at Specific Arbitrary Regions on Hematite (α-Fe₂O₃)

We performed photoelectrochemical polymerization (PEP) on hematite (α-Fe₂O₃) to synthesize PEDOT (poly(3,4-ethylenedioxythiophene)) in specific arbitrary regions with a high 2D flexibility. PEDOT is a conductive polymer that is highly attractive due to its ability to enhance conductivity and stability of electrical activity when used as crosslinkers or fillers. Hematite, as a semiconductor material with a bandgap of 1.9-2.2 eV, generates minority charge carriers (holes) with a short diffusion length when exposed to visible light. we confirmed the synthesis of PEDOT on hematite using cyclic voltammetry, which exhibited similar characteristics to PEDOT synthesized on Pt and ITO electrodes. Furthermore, we demonstrated the synthesis of PEDOT at lower voltages via PEP compared to voltages in the absence of light illumination. Additionally, by applying the appropriate voltage and utilizing a digital mirror device (DMD) to expose patterned light at specific arbitrary regions, we generated patterned PEDOT at the regions with a high 2D flexibility. We expect that these results can be utilized to enhance sensitivity and improve the fine-tuned functionalities of various semiconductor-based devices, including solar cells, supercapacitors, and biosensors.