Conformal Broad-Spectra Laser Sensing Array from Ferroelectric Polymer Composites

Photoelectric sensors based on charge-coupled device (CCD) and complementary-metal-oxide-semiconductor (CMOS) used to be planar image sensors due to the rigidity of the base materials. Moreover, they are limited to a narrow reaction wavelength range. Here, a conformal broad-spectra laser sensor based on a flexible metal-ferroelectric-metal photocapacitor is promoted. The photocapacitance signal is attributed to the photothermal effect of copper (Cu) electrode and gold nanoparticles (Au NP), and the temperature-dependent property of the dielectric constant of poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE). Cu/PVDF-TrFE/Cu and Cu/Au NP@PVDF-TrFE/Cu flexible photocapacitors have a reliable photocapacitive response from -60 to 60 degrees C. Meanwhile, both photocapacitors respond from 265 to 980 nm due to the absorption of light by the composite structure, which can be used for broad-spectra photodetection. The addition of a small amount of Au NP (0.05 vol%) effectively improves the photoresponsiveness of the device. Real-time photodetection is realized on a hemispherical surface, and these photocapacitors with conformal characteristics are expected to gain application in an omnidirectional broad-spectra laser alarming system. This work demonstrates the first conformal broad-spectra laser sensing array from ferroelectric polymer. Broad-spectra lasers (405, 532, 633, and 980 nm) illuminating on copper electrodes and gold nanoparticle fillers lead to a significant temperature rise in the ferroelectric polymer matrix due to the photothermal effect, which results in a capacitance change of the composite capacitors. image