Lanthanum-modified lead zirconate titanate based paint for sensor and energy harvesting applications

Abstract

Multi-functional lanthanum modified lead zirconate titanate/paint (PLZT/paint) nanocomposite films on copper substrates were fabricated using a conventional brushing technique. Atomic force microscopy (AFM) was utilized to study surface morphology of the films to assess the surface roughness and dispersion of the PLZT nanoparticles in the paint matrix. Non-structural functions such as dielectric and energy harvesting properties have been studied. Results indicate an increase in dielectric constants (ε′, ε″) with increasing temperature and PLZT nanoparticle concentration in the paint matrix. The ac conductivity studies of the nanocomposites were in excellent agreement with the Jonscher law: ${\sigma _{ac}}={\sigma _{dc}}+~A{\omega ^s}$, where s is an exponent that decreased with an increase in temperature. The leading ac conduction mechanism in nanocomposite films was found to be correlated barrier hopping (C.B.H.). The activation energy of nanocomposite films was found to decrease with an increase in the concentration of PLZT nano-particles. The pyroelectric coefficient and figure of merits were enhanced with PLZT nanoparticle loading and increased temperature, making it an attractive candidate for a readily deployable pyroelectric sensor and potential thermal harvesting applications. The output voltage and power for a PLZT/paint harvester with a broad frequency response operating in the − 31-piezoelectric mode were 51.7 mV and 0.38 µW, respectively. Output voltage and power were increased with the application of thermal oscillations.