Pyroelectric detectors based on high-performance PMN-PT single crystals

摘要

Single crystal of Pb(Mg_(1/3)Nb_(2/3))O_3-PbTiO_3 (PMN-PT), as one of the best pyroelectric materials, was first discovered by Chinese scientist. In this paper, PMN-PT was selected as pyroelectric detector material. Firstly, an electrically calibrated pyroelectric detector with special structure was developed for calibration of radiation. The sensitive area of the detector is 10mm×10mm and the entrance aperture is Φ8mm. The research about the coating film on the surface of the sensitive area was carried out. Carbon nanotubes (CNTs) were selected as the coating material. The responsivity of the detector is about 18.3 V/W at 14 Hz. The detectors were used to establish an electrically calibrated system with uncertainty less than 4% at room temperature. The relative deviation of measurement is less than 3% between 0.2 W/m~2 and 200 W/m~2, and the relative deviation is less than 5% between 0.002 W/m~2 and 0.02 W/m~2. Secondly, a 128×1 linear array was designed and fabricated. The responsivity of the linear array is 3.5×10~4 V/W at 10 Hz, and the noise equivalent radiant power (NEP) is 0.4 nW. The pyroelectric array and CMOS read-out circuit were electrically bonded by ultrasonic bonding process to be uncooled focal plane array (FPA). The FPA was tested under different radiation intensity. These results lay a foundation for the development of high-performance uncooled pyroelectric FPA based on novel ferroelectric single crystals.