Fabrication and performance of a NiMn2O4/LaNiO3 composite film detector with multi electrodes for night vision imaging application

Abstract

Detection performance of a composite structured infrared detector of NiMn2O4/LaNiO3 films has been studied. The thermally sensitive film of NiMn2O4 and conductive oxide film of LaNiO3 were deposited on silicon substrate by using a sol-gel method. The transmission and reflection measurements revealed that the absorption of the composite films grows from 6 to 8% (bare NiMn2O4) to about 40 %–70 % by increasing the LaNiO3 film thickness to 600 nm. A broadband optical detector was built by using the composite film. As revealed by the detection experiment, the detector showed a time constant of 0.45 ms to a 1550 nm light source, which was an order faster than the traditional thermal detectors. The detectivity of the detector was measured to be 0.37 × 107 cm·Hz0.5/W (Johnson noise) to a mid-infrared source, which can be improved to be about 109 cm·Hz0.5/W by using thermal isolation structures. The composite structure detector showed potentials in the application of night vision imaging.