ACTIVE BROADBAND PERFECT ABSORBER BASED ON PHASE CHANGE MATERIAL FOR SOLAR ENERGY HARVESTING

Abstract

. In this paper, a wide-angle, polarization-independent broadband perfect absorber based on GeTe phase-change materials is reported. It is found that the bandwidth of the absorber reaches 600 nm, and the absorptivity is higher than 90%. Moreover, absorptivity in the range of 400 ~ 1000 nm is higher than 85% when the incident angle is increased from 0 to 40 degrees. Although the geometry size of the absorber is fixed, absorption bandwidth and absorptivity can still be actively adjusted by changing the phase-change degree. The underlying physical mechanism of this absorber is ascribed to the localized surface plasmon resonance of Ag nanopillars as well as the Fabry-Pérot (FP) resonance between GeTe and bottom Ag films. This proposed perfect absorber design has great potential in solar energy harvesting, etc.