Thin-film semiconductor electrodes deposited on pyroelectric ceramics: Application to compact spectrally selective pyroelectric IR sensors

• Published in: Sensors and actuators. A, Physical Physical, 1993-06, Vol.37, p.507-511
• Main Authors: de Frutos, J., López, F.
• Format: Article
• Language: English
• Subjects: Bolometer; infrared, submillimeter wave, microwave and radiowave receivers and detectors; Exact sciences and technology; Infrared, submillimeter wave, microwave and radiowave instruments, equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/0924-4247(93)80087-W

Ferroelectric materials like lead calcium titanate ceramics have been demonstrated to be excellent materials for pyroelectric detectors. They are usually covered with electroded black gold. This material is extensively used to obtain both a fair IR absorption and a good electrical contact. Spectrally selective compact IR sensors for specific applications could be obtained by means of vacuum deposition on the pyroelectric substrate of the specific multilayer IR filter. However, very smooth substrates are required for proper adhesion of the multilayer, which is not the case for black gold layers. Besides, these layers do not possess the optical properties required in the filter's design and development process. Semiconductors like germanium or silicon are typical IR optical materials widely used in optical multilayers. Vacuum-evaporated Ge thin films have been deposited onto pyroelectric lead calcium titanate ceramics. In this work, a new system to improve the performance of lead calcium titanate ceramics for an infrared sensor is proposed. Studies have also been performed in order to establish the behaviour of this material as both an electrode and first layer. The feasibility of obtaining compact spectrally selective pyroelectric IR sensors has also been proved.