Layer-by-layer fabrication of highly transparent polymer based piezoelectric transducers

Abstract

The fabrication of highly transparent piezoelectric transducers is of increasing interest in the scientific and technological community. In this work, polymer based piezoelectric transducers were fabricated by the direct deposition of each layer forming the transducer on the desired substrate, avoiding the use of coupling layers. Transparent conductive oxide (TCO) electrodes were deposited by magnetron sputtering and piezoelectric films based on the copolymer poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) were deposited by spin-coating. All layers were processed and characterized to obtain a highly transparent piezoelectric P(VDF-TrFE) transducer with a strong adhesion between layers and preserving the piezoelectric response of the copolymer film. Indium tin oxide (ITO), gallium-doped zinc oxide (GZO) and aluminium-doped zinc oxide (AZO) were evaluated, and the best performance was obtained with AZO. The optimized transducer features an optical transmittance higher than 75% in the visible spectral range and a piezoelectric coefficient vertical bar d(33)vertical bar of 34 pC.N-1.