Pyroelectric properties in sol–gel derived barium strontium titanate thin films using a highly diluted precursor solution

The pyroelectric coefficient and pyroelectric infrared response in the sol–gel derived Ba0.8Sr0.2TiO3 thin films have been studied for possible infrared detector applications. The measured pyroelectric coefficient is larger than 3.1×10−4 C/m2 K at temperatures ranging from 10 to 26 °C and reaches the maximum value of 4.1×10−4 C/m2 K at 16 °C. The infrared detectivity of 4.6×106 cm Hz1/2 W−1 has been obtained at 19 °C and 10 Hz in the Ba0.8Sr0.2TiO3 films deposited on thick (500 μm) platinum coated silicon substrates. The better infrared response can be expected by the improvement in the thermal isolation of pyroelectric element and the electrode materials.