Near infrared detection based on sputter-deposited Mn-Co-Ni-O films with a MSM structure

Abstract

This work explores high-quality infrared detectors based on Mn-Co-Ni-O (MCNO) films, which were deposited by radio frequency magnetron sputtering at different temperatures ranging from 200 to 600 °C. Increasing the growth temperature was beneficial for forming smoother surfaces, higher crystallinity, and higher concentrations of Mn3+ and Mn4+ ions. However, it also resulted in a decrease in the thermal activation energy and temperature coefficient of resistance (TCR). MCNO-based metal–semiconductor-metal (MSM) structured detectors are highly sensitive to 885 nm infrared light, with the detector grown at 200 °C exhibiting the greater on/off ratio of 13.15, the largest responsivity of 0.23 A/W@-15 V, and the highest specific detectivity of 3.74 × 108 Jones and a rapid response/recovery time of 31.2/20.4 ms. This was attributed to due to its largest TCR value of −6.42 %/K, nano-pyrometric cone crystal grains on the surface, the largest Ov concentration, the lowest activation energy of Ov and electron-hole recombination efficiency, relatively high concentrations of Mn3+ and Mn4+ ions and lower resistance at 293 K. This research demonstrated that optimizing growth temperature is an effective method for significantly improving the properties of MCNO-based MSM structured detectors.