Characteristics of Pyroelectric Infrared Array Detector Made of PbTiO₃ Ceramics

Abstract

A one-dimensional pyroelectric array detector as a multi-element infrared sensor has been developed by using a new sheet forming method made of PbTiO 3 bulk ceramics. This simple fabrication process is cost effective and enables us to control the film thickness accurately, thus decreasing the sensitivity variations that exist in one detector and among different detectors to within 10%. A pyroelectric detector responsivity of 2×10 4 V/W can be obtained at 10 Hz chopping frequency. A specific detectivity D * of 0.8×10 8 cm· Hz 1/2 /W has been achieved. Furthermore, this detector has a sufficient sensitivity for performances at high chopping speeds up to 100 Hz. The time constant of this pyroelectric detector is about 8.6 ms, so the detector has a shorter response time compared with the commercially available conventional pyroelectric detector. The cross talk, which influences the output for the adjacent elements, is less than 10%. By using this high performance pyroelectric array detector, the thermal sources at lower temperatures than environmental conditions can be detected with high sensitivity, as much as the thermal sources at higher temperatures. The output voltage for the detector was gradually decreased as the atmospheric temperature increased.