Structural and electrical properties of semiconducting YBa2Cu3O6+x thin film by sol-gel for uncooled infrared detectors

Abstract

Uncooled pyroelectric infrared detectors based on semiconducting YBa2Cu3O6+x (YBCO) thin films were investigated. YBCO precursor solutions were prepared using the sol-gel method and YBCO films were fabricated by spin coating. The structural and electrical properties at varying annealing temperatures were studied. From differential thermal analysis and thermogravimetry (DTA-TG) results, an endothermic peak was observed at around 700 degrees C, due to the formation of a tetragonal phase. The crystal structure of the YBCO film annealed at 600 degrees C similar to 800 degrees C was a polycrystalline tetragonal phase. All specimens displayed a second phase (BaCO3). The YBCO film sintered at 700 degrees C showed a small grain size and smooth surface. The temperature resistance coefficient (TCR), responsivity and detectivity of the YBCO film sintered at 700 degrees C were -2.76%/degrees C at room temperature, 36.17V/W and 4.77 x 10(6) cmHz1/2W(-1), respectively.