Enhancing pyroelectric detection performance of Na _0.5 Bi _0.5 TiO ₃ ‐based lead‐free ceramics via thermoelectric effect

Abstract Pyroelectric sensors based on pyroelectric effect have a wide range of applications. However, the use of lead‐containing materials limits their development. In this paper, Na 0.5 Bi 0.5 TiO 3 ‐Na 0.5 Bi 4.5 TiO 15 ‐Mn lead‐free pyroelectric ceramics are used as sensitive materials to prepare pyroelectric sensors. Na 0.5 Bi 0.5 TiO 3 ‐Na 0.5 Bi 4.5 TiO 15 ‐Mn ceramics can achieve 7.58 × 10 –4 C·m −2 ·K −1 high‐room‐temperature pyroelectric coefficient and depolarization temperature of 151 °C. Due to the low dielectric constant and loss caused by Mn doping, the high detection rate value of 24.382 μPa −1/2 is obtained. The voltage response rate and specific detection rate of the sensor prepared on this basis can attain the JC‐T 2397‐2017 ( ε r > 200, tan δ < 5%, T c > 200, p > 3.50 × 10 –4 C·m −2 ·K −1 ) application standard of pyroelectric infrared detectors. Thermoelectric cooler is proposed to adjust the temperature of the sensor, and its voltage response to human radiation is measured. Harnessing the superior pyroelectric attributes of advanced materials and connectable devices, the nascent thermoelectric–pyroelectric detection method is poised to be a subject of intensive investigation and development.