Optical Characterisation of La0.7Sr0.3MnO3 Thin Film Based Uncooled Bolometers

This paper reports the potentialities of the manganese oxide La0.7Sr0.3MnO3 (LSMO) for the realization of uncooled thermal detectors. Close to room temperature, LSMO exhibits a metal-to-insulator transition, where a large change of electrical resistance versus temperature occurs. The tested sample is a 100 nm thick epitaxial LSMO thin film deposited on a SrTiO3 buffered Si substrate. The optical responsivity and electrical noise were measured in a frequency range of 1 Hz-100 kHz, thus enabling the estimation of specific detectivity. It is shown that due to the very low 1/f noise level, in this epitaxial film deposited on silicon wafer, LSMO thermal detectors can exhibit competitive performances at room temperature.