Preparation And Application Research Of Pyroelectric Infrared Detector Based On High Curie Point Relaxor Ferroelectric Single Crystal

With the rapid development of the Internet and the Internet of Things?IOT?,people's life and production are developing in a more automated and intelligent direction.The requirements of sensor quality in various industries are becoming higher,and the demand of sensor is also increasing.Pyroelectric infrared detectors have been paid more and more attention because of its characteristics of no refrigeration,no bias,simple device structure,and wide spectral response.The key of pyroelectric infrared detector development is the pyroelectric materials.The relaxed ferroelectric single crystal PMNT with high pyroelectricity,adequate dielectric constant and low dielectric loss,is expected to be next generation of commercial pyroelectric materials.In this paper,the pyroelectric infrared detectors based on the third generation of relaxor ferroelectric single crystal Mn-PIMNT?15/55/30?and their applications have been investigated.The research content and results obtained are as follows:?1?Pyroelectric infrared detector model establishment and optimization theory.For the guidance of research work,the light-to-heat and heat-to-electric conversion of pyroelectric chip based on Mn-PIMNT?15/55/30?crystal has been analyzed.The relationship between the temperature change of the pyroelectric chip and the pyroelectric current with the frequency of infrared radiation have been analyzed,also the integrated preamplifier circuit of the detector has been analyzed.In order to improve the anti-interference ability of the detector,a compensated pyroelectric detector has been studied.The relationship between the voltage response rate of the detector and the modulation frequency has been analyzed,and the optimal frequency usage range of the detector has been determined.On the other hand,the main noise sources under different frequency range has been analyzed,which will provide guidance for the preparation of the detectors and performance optimization.?2?The preparation and performance optimization of pyroelectric infrared detector.Uncompensated and compensated detector pyroelectric infrared detector based on Mn-PIMNT?15/55/30?single crystal have been successfully fabricated.The voltage response rate of the uncompensated and compensated detector are8×10⁴ V/W at 10 Hz,and the noise density of the compensated detector is higher than the uncompensated detector,which is consistent with the theory analysis results of the detector;The specific detection rates of the uncompensated and compensated detector are 5.1×10⁸cm?Hz^1/2/W and 3.6×10⁸ cm?Hz^1/2/W,respectively,reaching the international advanced level.As comparing with the uncompensated detector,the compensated detector's signal is more stable and less susceptible to environmental temperature changes and vibration,which make it more suitable for use in harsh environments.?3?Application of pyroelectric infrared detector based on Mn-PIMNT?15/55/30?single crystal in gas sensors.Through the research on the principle of gas analysis,the calculation formula of gas concentration is derived and optimized,which would be help for the accuracy and stability of the calculation;The methane gas sensor was designed.Finally,the relationship between the gas concentration and the signal voltage of the detector was obtained,showing a good application prospect of Mn-PIMNT series single crystal.