Pyroelectric Thermal Energy Harvester Based on Sol‐Gel‐Derived PLZT Films

Abstract

The present work focuses on studying the pyroelectric properties of chemical solution deposition‐grown Pb1−xLax(Zr0.4Ti0.6)O3 films on nickel substrate which are annealed at constant temperature of 650 °C with lanthanum concentrations ranging from x = 2–8% respectively. Structural studies reveal polycrystalline nature in all the PLZT films. The dielectric constant values rise from 497 to 1048 as La doping concentration rises from 2% to 6% at a constant frequency of 1 MHz, reaching a maximum value of 1048 for 6% La doping with little variation in dielectric loss between 0.03 and 0.05. As La doping level increases from 2% to 6%, the remnant (Pr) and saturation (Ps) polarization values increase from 12 to 47 μC cm−2 and 18 to 53 μC cm−2 respectively. The leakage current is found to be 2.68 × 10−8 A for 2%‐doped PZT film and it reduces to 2.94 × 10−10 A for PLZT (6% doping) film. The influence of lanthanum doping on the pyroelectric properties has been studied in detail. The value of pyroelectric coefficient (p) is varied from 240 × 10−3 to 980 × 10−3 Cm−2 K−1 and current responsivity is varied from 960 × 10−10 to 3920 × 10−10 mV−1 with the variation in lanthanum content from 2% to 6%, respectively. The promising pyroelectric results found in PLZT films encourage these films in energy applications field.