Research On LiTaO₃ Pyroelectric Material And Unit Structure Simulation

LiTaO3 is an excellent pyroelectric materials and is widely used in the preparation of pyroelectric detectors for military and commercial purposes, as the result of its small size, high cost performance, and no pollution in its production. This paper aims to research Terahertz Pyroelectric Unit Devices that are based on LiTaO3.The high performance LiTaO3 films made by Sol-gel are tested in the perspective of dielectric, pyroelectric, and ferroelectric performances. Then both modeling and simulation are realized with the help of detectors that are based on experimental materials. Therefore, this paper provides theory basis for subsequent preparation of Terahertz Pyroelectric Unit Devices. The main studies of this paper are as follows:A new way called Sol-Gel to prepare high concentrations of LiTaO3 colloidal solution is employed in the experiment. The author takes 1.2-propanediol that has high solubility as the solvent to prepare Li TaO3 solution, the concentration of which reaches 1.2 mol/L.This attributes to the great reduction of repetition of spinning and the experiment period. The production of films is also more efficient.Technology method of LiTa O3 films and its dielectric, leakage, and pyroelectric performances are studied. The study includes:(1) preparing LiTaO3 films on Pt and FTO substrates, the author discusses the influence of different substrates, different annealing situations to LiTaO3 films and to the dielectric constant and loss;(2) the author also does the research on ferroelectric and pyroelectric performances of LiTa O3 film on Pt and FTO substrates. In the experiment, the dielectric losses of LiTaO3 on Pt and FTO substrates are 0.006 and 0.011 at the frequency of 10 kHz. Under the same condition, the dielectric constants are 45 on Pt substrate and 54 on FTO substrate, at the same time their leakages are 4.67×10-8 A/cm2 and5.12×10-7 A/cm2;the pyroelectric coefficient are1.43×10-8 μC/(cm2·K) on Pt substrate and 1.22×10-8 μC/(cm2·K) on FTO substrate. As for voltage response of merit and detection merit, they are 0.99×10-10 C·cm·J-1 and 0.61×10-8 C·cm·J-1. This proves that LiTaO3 films are better than other pyroelectric materials.Intellisuite is employed to carry out bench type and cone modeling and simulation of Terahertz pyroelectric detectors. The detectors are based on LiTaO3 films. Compared with traditional bench type structure in the influence of size, contact area, cone structure performances better in film detectors.