$Pb_{1-x}La_{x}Ti_{1-x/4}O_3$(x=0.1)(PLT(10)) 강유전체 박막에서 동적 초전특성의 주파수 의존성에 관한 연구

A study on the Frequency Dependence of Dynamic Pyroelectric Properties for $Pb_{1-x}La_{x}Ti_{1-x/4}O_3$(x=0.1)(PLT(10)) Ferroelectric Thin Film

The fabricated La-modified lead titanate (PLT) thin flirt without poling treatment was investigated for modulation frequency dependence of pyroelectric properties by the dynamic method. $Pb_{1-x}La_{x}Ti_{1-x/4}O_3$PLT (x=0.1) thin film having 10 mol% La content was deposited on a Pt/$TiO_{x}$/$SiO_2$/Si substrate by sol-gel method. The PLT(10) thin film exhibits a relatively excellent dielectric property. The pyroelectric coefficient (p) of the PLT(10) thin film is 6.6 x $10^{-9}$C/$\textrm{cm}^2$.K without frequency dependence. The figure of merits for the voltage responsivity and specific detectivity are 1.03${\times}$$10^{-11}$/C.cm/J and 1.46 x $10^{-9}$C.cm/J, respectively. The PLT(10) thin film has voltage responsivity ($R_{V}$) of 5.15 V/W at 8 Hz. Noise equivalent power (NEP) and specific detectivity (D＊) of the PLT(10) thin film are 9.93 x $10^{-8}$W/Hz$^{1/2}$ and 1.81 x $10^{6}$ cmHz$^{1/2}$/W at the same frequency of 100 Hz, respectively. The results means that PLT thin film having 10 mol % La content is suitable for the sensing materials of pyroelectric IR sensors.