Specific phase modulation and infrared photon confinement in solar selective absorbers

Abstract Nanocermet-based solar selective absorbing coatings harvesting solar energy in the form of heat provide deliverable and reliable scheme utilized in Concentrating Solar Power (CSP) system. However, high-temperature instability and pretty high infrared emissivity are still major hurdles on the way towards more demanding applications. Here, we report a hybrid strategy via incorporation of alloy nanoparticles, specific phase-created reflective layer and infrared photon dissipation confinement effect, to realize a target coating stable at 650 °C with record optical performance (an ultralow emissivity of 7.9 %@500 °C and a solar absorptance of 93 % after 300 h vacuum annealing). Such a synergetic enhancement on both the thermal stability and optical performance is mainly ascribed to the outpouring element reservoir in the tri-layer cermet structure with faded infrared extinction volume on the one hand, and phase structure modulation-derived arresting infrared reflectance on the other. More importantly, this work demonstrates significant conceptual and nanotechnology advances into designing and improving such systems.