High-performance pyroelectric infrared (IR) detectors have been fabricated using tantalate-doped lithium niobate LiNb1-xTaxO3 (abbreviated as LNT, with x=0-1.0) thin films deposited on Pt(111)/Ti/SiO2/Si(100) substrates by diol-based sol-gel processing, in which, tantalate (Ta) is adopted as dopant in lithium niobate. The randomly oriented LNT thin film exhibits a relatively small dielectric constant and a large pyroelectric coefficient. The pyroelectric characteristics of detectors with various tantalate contents, as a function of modulation frequency, were investigated. It was found that LiNb0.8Ta0.2O3 had the largest voltage responsivity of 7020 (V/W) at 70 Hz, and a specific detectivity (D*) of 7.76 x 10(7) cm Hz(1/2)/W at 200 Hz. These results indicate that the LNT thin film with x = 0.20 is most suitable for application as high-performance pyroelectric thin-film detectors. (c) 2007 Elsevier B.V. All rights reserved.