Swift Photochromic Smart Window Based on Plasmonic Yolk-Shell Nanophosphors

摘要

Herein, the fabrication of eccentric Ag@Void@Y_2SiO_5:Pr~(3+) plasmonic yolkshellnanophosphors (PYSNPs) with high up-conversion efficiency, andtheir incorporation on photochromic WO3 layers, is demonstrated to fabricatephotochromic smart windows with high coloration contrast and swiftcolor change. The up-conversion efficiency of the Pr~(3+) ion-doped Y_2SiO_5(Y_2SiO_5:Pr~(3+)) nanoshells is enhanced by about 50 through the incorporationof carefully designed plasmonic Ag cores placed inside their hollow cavities.Introduction of these geometry-optimized plasmonic nanophosphors atthe surface of photochromic WO_3 films results in about 24-fold and tenfoldenhancements of their coloration rate and kinetic constant, respectively. Thestrategy adopted for designing and fabricating the Ag@Void@Y_2SiO_5:Pr~(3+)PYSNPs and their subsequent incorporation in conventional photochromicfilms offers an exciting approach for fabricating photochromic smart windowswith dynamically controlled transmission of solar radiation, which is a promisingtechnology for reducing energy consumption associated with heating,ventilation, and air-conditioning of buildings.