Sol-gel derived barium strontium titanate thin films for uncooled infrared detector array applications

Columnar Ba0.8BSr0.2TiO3 films with a grain size of 100 to 200 nm have been obtained from a 0.05M precursor solution. Electrical measurements indicated these films showed a pyroelectric coefficient of 4.1 x 10(4) C/m(2)K at room temperature, arid a leakage current of 1.42 x 10(-7)A/cm(2) under 100 kV/cm electrical field. The Ba0.8BSr0.2TiO3 films have been used for fabricating a 1 x 16 elements infrared detector linear array with a bulk micromachining technique. The array pixels with a sensitive area of 500 x 300 mum(2) have a detectivity of 2.3 x 10(8) cmHz(1/2)W(-1) at 23 C and 35Hz. By using these infrared detector arrays, thermal images were successfully obtained at room temperature. These results indicate the sol-gel derived Ba0.8BSr0.2TiO3 films from a 0.05M precursor solution are suitable for uncooled infrared detector array applications.