Near-infrared-shielding energy-saving borosilicate glass-ceramic window materials based on doping of defective tantalum tungsten oxide (Ta0.3W0.7O2.85) nanocrystals

Abstract

NIR-shielding window materials were fabricated by direct embedding of Ta 0.3 W 0.7 O 2.85 nanocrystals in bulk borosilicate glass-ceramics during a facile melt-quenching process. Optical and thermal performance of the prepared windows can be adjusted by varying the concentration of H 2 WO 4 and Ta 2 O 5 in the starting materials. The optimized window fabricated from raw materials containing 4.5 mol% H 2 WO 4 and 0.3 mol% Ta 2 O 5 exhibited high visible light transmittance 74.4% and strong NIR-shielding ability ΔT = 68.9%. Its thermal insulation performance is much better than soda lime glass or ITO glass, and its visible light transmission is higher than cesium-tungsten-bronze-based film coated glass. The distribution of Ta 0.3 W 0.7 O 2.85 functional nanocrystals in the glass matrix was confirmed by sample characterization using XRD, Raman, XPS, HRTEM and EDS. The NIR-shielding property has been attributed to local surface plasmon resonance due to oxygen vacancies in the Ta 0.3 W 0.7 O 2.85 nanocrystals. This study sheds a light on fabricating energy-saving windows with a tunable NIR-shielding performance.