3D-Printed Photoactive Semiconducting Nanowire–Polymer Composites for Light Sensors

We demonstrated 3D-printed photoactive composites for light sensors. The composites consist of semiconducting polymer nanowires dispersed in an insulating polymer matrix through a thermo- or photocuring process. The nanowires formed percolated networks for charge-carrier collection at a very low nanowire volume concentration. Photodetectors had been fabricated with such composites and obtained a low leakage current density of 25 nA cm^–2, a large conductivity change of 18025 times upon light irradiation (1 sun), and a high specific detectivity of 4.5 × 10¹⁰ Jones. The composite precursors before curing had been used as paints on different surfaces including wood, cardboard, and glass fiber cloth to create photoactive coatings on these surfaces. The precursors had also been used for 3D printing to create photoactive structures with a mechanical modulus of 4 GPa and an ultimate strength of 36 MPa.