Abstract
The outstanding pyroelectric coefficient p of Mn:PIN–PMN–PT makes it an interesting material for application in pyroelectric infrared detectors. In comparison to the standard material lithium tantalate (LT), the pyroelectric coefficient is higher by a factor of 4. On the other hand, the dielectric permittivity εp is about one order of magnitude higher compared to LT. Due to the higher permittivity, the resulting Figures of Merit (FOM) show the highest performance advantages for Mn:PIN–PMN–PT in the lower frequency range between 1 Hz and 10 Hz. The FOM FR of 278 · 10−12 m/V exceeds by half an order of magnitude the value of LT of 54 · 10−12 m/V. Outstanding specific detectivities around D* ≈ 1.0 · 109 cm√Hz/W at low frequencies even at a relatively low chip size were achieved. The detector fabrication needs adaption of the processes to avoid depolarization due to high temperature impact or mechanical stress.
Highlights
The key component of a pyroelectric detector is a thin plate of a pyroelectric material whose electrodes become oppositely charged when heated
In comparison to the standard material lithium tantalate (LT), the pyroelectric coefficient is higher by a factor of 4
Sputtered PZT thin films were evaluated for pyroelectric applications and still used in pyroelectric detectors and 1D arrays,6,7 but single crystalline lithium tantalate (LiTaO3, LT) is the preferred material for industrial and medical applications due to its good performance combined with high stability and reliability
Summary
The key component of a pyroelectric detector is a thin plate of a pyroelectric material whose electrodes become oppositely charged when heated. This unique effect was already known in the ancient world and was given the name pyroelectricity in 1824 by Brewster, the broad application in infrared detectors was introduced in the early 1970s.1,2. Sputtered PZT thin films were evaluated for pyroelectric applications and still used in pyroelectric detectors and 1D arrays, but single crystalline lithium tantalate (LiTaO3, LT) is the preferred material for industrial and medical applications due to its good performance combined with high stability and reliability.. The approach is dominated from a pragmatism to obtain reproducible material properties and treatments with regard to the application in pyroelectric detectors
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