Enhanced Pyroelectric Performances in Textured Na0.5Bi4.5Ti4O15 Ceramics for Infrared Detection

The pyroelectric effect is extensively used in infrared imaging, detection systems, military equipment, and smart furniture, which require pyroelectric materials to simultaneously possess a high pyroelectric coefficient (p) and a high Curie temperature (T-c) for circuit integration. However, the T-c of commercial lead zirconate titanate (PZT) is limited to 230 degrees C, imposing an insurmountable challenge in the integration. Here, we investigated the pyroelectricity in Na0.5Bi4.5Ti4O15 (NBT) with a high Curie temperature (similar to 660 degrees C), meeting the temperature requirements for integration. Textured NBT ceramics with a high degree of orientation (80%) were fabricated by using tape-casting, resulting in a p of 122 mu C m(-2) K-1, a 144% improvement over randomly oriented NBT ceramics. This method was also applied to doped NBT ceramics (NBTM-5Nb), achieving an impressive p of 252 mu C m(-2) K-1, representing a 400% improvement compared to randomly oriented NBT ceramics. Meanwhile, the textured NBTM-5Nb ceramics exhibit excellent figures of merit with F-i = 1.05 x 10(-10) m V-1, F-v = 0.09 m(2) C-1, F-d = 4.9 x 10(-5) Pa-1/2, comparable to the performance of PZT. Furthermore, the textured ceramics exhibit excellent thermal stability, with no performance degradation after annealing at 300 degrees C, rendering them suitable for circuit integration.