Comparison of dielectric property of lithium tantalate infrared detector prepared by sol-gel and IBED methods

Abstract

The novel uncooled lithium tantalate thin film infrared detector samples were prepared by Sol-Gel and IBED methods. The crystallisation, micrograph, dielectric property and current leakage of detector samples were investigated by XRD, SEM, impedance analyser and ferroelectric material analyser. The experimental results reveal both IBED and Sol-Gel lithium tantalate thin films have perfect cross-sectional micrograph. The Sol-Gel method is easy to control lithium tantalate stoichiometric proportion in the prepared films. The IBED method obtains perfect thin films only if the right ratio targets were used. The IBED samples annealed at 550°C have dielectric permittivity of 39.44 and dielectric loss of 0.045 at 100 kHz, the current leakage of 4.76 ´ 10–8A/cm2 at tested field of 400 kV/cm, and breakdown field up to 680 kV/cm. But the dielectric loss and current leakage of Sol-Gel samples are larger than those of the IBED samples. It means the IBED process is better to prepare the novel detectors.