Simulation Study Of Pyroelectric Detector Unit Structure

Pyroelectric detector is a kind of thermal detector,which is a sensor which can measure the energy of infrared radiation by using the thermal effect of infrared and the pyroelectric effect of material.It has been widely used in military and civil fields because of its advantages such as room temperature detection,no external bias,high detection rate,high reliability,wide response spectrum,fast response speed and so on.Pyroelectric detector sensitive units design in this paper,considering the application background of background radiation measurement.The performance of pyroelectric detector is affected by several factors,such as absorption of infrared radiation,thermal temperature rise and mechanical stability.In order to study the related features of pyroelectric detector,IntelliSuite microelectromechanical finite element simulation analysis software was used to construct the three-dimensional finite element model of the structure of three kinds of sensitive element based on the sensitive element area of 1200?m×1200?m.The effects of different support parameters on the thermal and mechanical properties of pyroelectric detectors are analyzed by simulation.The influence of the shape and size of the support pillar on the pyroelectric detector is analyzed.The optimal structural parameters of the pyroelectric detector are obtained.Analysis of the effect of infrared absorbing film on the performance of pyroelectric detector by using Essential Macleod optical thin film simulation software.The thickness of each film in the absorption system was changed by the control variable method,and the optimal conditions of the pyroelectric film were obtained.The absorption rate of the film is mainly affected by the thickness of the absorbing layer.The thickness of the crystal layer of the lithium tantalate mainly affects the peak position of the absorption curve.When the structure of absorption layer of the sensitive unit adopts the 10 nm nichrome metal absorption layer,the lithium tantalate wafer is 9.5?m,and the reflection layer is 200 nm nichrome metal layer,the radiation absorption is highest in the experimental band 14~16 ?m.The simulation analysis of the absorption of the film is made for the small angle incidence.In the end,according to the results of thermal,mechanical and optical properties of pyroelectric detector,a kind of pyroelectric detector sensitive unit structure is obtained.Load heat flux density calculated systematically.The temperature rise curve of the temperature rise region of the detector element is extracted,and the average pyroelectric current output from the temperature rise to the thermal equilibrium is calculated.It is of great significance to further estimate the performance of pyroelectric detectors for the structural design of pyroelectric detectors.