Enhanced performance of Mn-Co-Ni-O thermosensitive material by Cu and Sc co-dopants for uncooled infrared detector

We prepare undoped Mn1.5Co1Ni0.5O4 and Cu and Sc co-doped Mn1.5Co1Ni0.25CuxSc0.25−xO4 (x = 0.05, 0.1, 0.15) films on Al2O3 substrate by chemical solution deposition method. The crystallinity, surface morphologies, electrical transport property, optical property, and 1/f noise property of these films are characterized. It shows that the Mn1.5Co1Ni0.25Cu0.15Sc0.1O4 film possesses excellent electrical transport, optical and 1/f noise properties compared with the other films. The absolute temperature coefficient of resistance and characteristic temperature of the Mn1.5Co1Ni0.25Cu0.15Sc0.1O4 film are higher than that of Mn1.5Co1Ni0.5O4 film, while its resistivity of 250 Ω·cm at 295 K is half of that Mn1.5Co1Ni0.5O4 film. The transmittance and reflectance spectra of the films are measured and analyzed in the range of 0.55–2.0 µm, all the films show similar absorption structures in the measured spectrum. The 1/f noise of the co-doped Mn1.5Co1Ni0.5O4 films decreases significantly. The (γ/n)0.5/|TCR| value of the Mn1.5Co1Ni0.25Cu0.15Sc0.1O4 reaches 2.3 × 10−12 cm1.5 K/% at 295 K, which is two orders lower than that of Mn1.5Co1Ni0.5O4 film. Our results discover a thermosensitive material with excellent performance, which is expected to be applied to high performance uncooled infrared detectors.