Pyroelectric IR Detectors Using Periodic Inverted Domains of LiTaO3

In this paper, a new-structure pyroelectric infrared detector is proposed, which consists of interdigital electrodes deposited on periodic inverted domains of ferroelectric crystal. Since only a shallow region close to the crystal surface is pyroelectrically active in this structure, the surface charges are quickly induced in response to IR irradiation and this structure therefore provides us with a high responsivity. A pyroelectric detector fabricated using periodic antipolar domains formed by selective proton exchange and subsequent heat treatment of LiTaO3 crystal is experimentally demonstrated to exhibit a high current responsivity in high frequency range of IR power modulation.