Properties of Infrared High Reflectance Mo Film for Solar Selective Coatings by MF Sputtering

摘要

Mo thin films were prepared by Mid-Frequency twin target magnetron sputtering as the high reflectivity coating in high temperature solar selective coating. The structure and optical properties of the coatings were studied by X-ray diffraction, scanning electron microscopy and Fourier Transform Infrared Spectrometer and spectrophotometer, the optical constants were inversely calculated by Handley equation. The highest infrared reflectivity of 94% reached at the bias voltage of -150 V and sputtering current 12A of the Mo cathode source, which satisfy the requirement for low thermal emittance solar selective coating applications. The thin films with body centered cubic structure grew along the (110) surface as column crystal, optical constants of Mo thin film were similar with bulk Mo. The thermal emittance of the infrared high reflectance Mo based selective absorber coating can control in 0.15 (400°C).