(Mn, Sb)-doped PZT and Nb-doped PZT uncooled IR detectors

Mn and Sb-doped Pb(Zr, Ti)O3 (PMSZT) and Nb-doped PZT (PNZT) thin film IR detectors have been integrated with Si substrates. A conducting YBCO layer in the IR detector was used as an atomic template for the epitaxial growth of the PMSZT and PNZT thin films, as well as a good IR-reflector. The epitaxial PMSZT and PNZT thin films were self-polarized and exhibited pyroelectric current even without any additional poling. The PMSZT and PNZT detectors were examined as to their pyroelectric current in response to the detector temperature. Doping with Mn and Sb into PZT and doping with Nb into PZT have been shown not only to decrease the Curie temperature Tc, but also increases pyroelectric current significantly in comparison with that of PZT thin films. The PMSZT detectors show high figures of merit, Fv of 1768 cm2/C and Fd of 0.048 (cm3/J)1/2 at 25 degrees C and Fd of 0.135 (cm3/J)1/2 at approximately 90 degrees C. The measured normalized detectivity D*, ranging from 2.5 X 108 to 6.0 X 108 cmHz1/2/W in the 2.5-19.5 micrometers wavelength band, indicated that PMSZT detectors are suitable for broad band IR detector applications. A PMSZT IR detector array with a micro-bridge for thermal isolation has also been fabricated.