Using spin coating method to prepare near room-temperature TCR of La0.7Ca0.205Sr0.095MnO3 films for uncooled infrared bolometers

•LCSMO films were prepared by facile and cost-effective spin coating.•TCR values enhanced from 1.9% K−1 at 210.5 K to 11.1% K−1 at 276.8 K .•Electrical properties were analyzed by DE mechanism, JT effect and PP model.•LCSMO films with high TCR are promising candidates for infrared bolometers. La0.7Ca0.205Sr0.095MnO3 (LCSMO) thin films were grown on LaAlO3 (100) substrates via facile spin coating at different sintering temperatures (Ts; Ts = 750, 900, 1100, and 1300 °C). The crystal structures of the films were detected by X-ray diffraction. The distortion of MnO6 octahedral was analyzed by Fourier transform infrared spectroscopy, while the surface morphology was observed using atomic force microscopy. In addition, the concentrations of itinerant electron and Mn3+/Mn4+ pairs were determined by X-ray photoemission spectroscopy. The electrical performance was analyzed using double exchange interaction, Jahn–Teller effect, and phenomenon percolation model. In general, the electrical properties of the films improved by increasing Ts. The peak temperature coefficient of resistivity (TCR) enhanced from 1.9% K−1 at 210.5 K (for Ts = 750 °C) to 11.1% K−1 at 276.8 K (for Ts = 1300 °C). These LCSMO films with optimized electrical properties exhibited a peak TCR temperature close to room temperature (290–300 K), making these films potential candidates for the uncooled infrared bolometers.