Quick response PZT/P(VDF-TrFE) composite film pyroelectric infrared sensor with patterned polyimide thermal isolation layer

• A single element infrared sensor using PZT/P(VDF-TrFE) composite thick film, with polyimide thermal insulation layer and thermal insulation tanks fabricated by laser micro-etching, were fabricated.
• The detectivity (D*) of the sensor was 1.9  × 108  cm Hz1/2 W−1 at 137.3  Hz modulation frequency and the thermal time constant of the infrared sensor τT was about 15  ms.
• The sensor show high detectivity and short response time, which is an essential advantage in infrared detectors and some other devices.

The fabrication method and the pyroelectric response of a single element infrared sensor based lead zirconate titanate (PZT) particles and polyvinylidene fluoride P(VDF-TrFE) copolymer composite thick film is reported in this paper. A special thermal insulation structure, including polyimide (PI) thermal insulation layer and thermal insulation tanks, was used in this device. The thermal insulation tanks were fabricated by laser micro-etching technique. Voltage responsivity (RV), noise voltage (Vnoise), noise equivalent power (NEP), and detectivity (D*) of the PZT/P(VDF-TrFE) based infrared sensor are 1.2 × 103 V/W, 1.25 × 10−6 V Hz1/2, 1.1 × 10−9 W and 1.9 × 108 cm Hz1/2 W−1 at 137.3 Hz modulation frequency, respectively. The thermal time constant of the infrared sensor τT was about 15 ms. The results demonstrate that the composite infrared sensor show a high detectivity at high chopper frequency, which is an essential advantage in infrared detectors and some other devices.