Long wavelength infrared detection based on Mn-Co-Ni-O thin films with dielectric-metal-dielectric absorptive structures

摘要

We reported the design and performance of a long wavelength infrared thermal sensitive detector based on the Mn1.56Co0.96Ni0.48O4 (MCNO) thin films. By using a NiCr absorption layer of some ten nanometers, we designed a quarter wavelength resonant cavity together with a Si3N4 anti-reflection layer, which improves the absorption in the infrared transparent window of 8-14 mu m. We calculated and analyzed the infrared absorption spectra at the atmospheric window, and the results showed that the non substrate absorption increases from less than 25% to 40-70% after coating with dielectric-metal-dielectric absorption layers. The blackbody responsivity enhanced by 2.1 times after the construction of the absorption films, which is about 0.84-1.68 x 10(7) cm.Hz(0.5)/W@10 Hz and close to the performance of the detector coated with black paints. The study contributes to the future development of large scale uncooled infrared MCNO thin film detection arrays.