Pyroelectric Property of the La-Doped PbTiO3 Thin Film as a Function of Modulation Frequency

초록

In this study, dynamic pyroelectric properties of La-doped PbTiO3 (PLT) thin films with dopant amounts of 5, 10, and 10mol% have been investigated. The voltage responsivity corresponding to the pyroelectric voltage is almost constant at low modulation frequency and decreases in proportional to the frequency at high modulation frequency. Among the films investigated, the PLT thin film with 10mol% of La (PLT(10) thin film) shows the best pyroelectric characteristics. The pyroelectric coefficient of PLT(10) thin film is 6.6×10-9 C/cm2K with no modulation frequency dependence. Its figures of merit for the voltage responsivity and specific detectivity are 1.03×10-11 Ccm/J and 1.46×10-9 Ccm/J, respectively. These results indicate that PLT(10) thin film is well applicable to the pyroelectric infrared sensor.