RT journal article
T1 Enhancing luminous transmittance and hysteresis width of VO2-based thermochromic coatings by combining GLAD and RGPP approaches
A1 Santos Izquierdo-Bueno, Antonio Jesús
A1 Martin, N
A1 Jiménez Ríos, Juan Jesús
A1 García Roja, R
A1 Morales Sánchez, Francisco Miguel
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
K1 Vanadium dioxide
K1 Glancing angle deposition
K1 Reactive gas pulsing process
K1 Rapid thermal annealing
K1 Vis-NIR spectrophotometry
K1 Thermochromism
K1 Smart glazing
AB This work reports on alternative strategies for improving the performance and thickness uniformity of VO2-basedthermochromic coatings by atmospheric oxidation of zigzag vanadium films sputtered at glancing angles inpresence of reactive oxygen. With the aim of scrutinizing the effect of deposition parameters, VO2–x films of 25,50 and 100 nm nominal thickness were deposited on glass substrates without reactive oxygen and by injectingoxygen pulses for 4 or 8 s every 16 s of deposition. Comprehensive structural, compositional and functionalcharacterizations of samples annealed at reaction temperatures between 475–550◦C for times ≤ 60 s confirmedthe synthesis of the VO2(M) phase and the development of singular microstructural and thermochromic featuresdepending on the duration of the oxygen injection pulses. Here, it was evidenced that longer oxygen pulses leadto significantly higher luminous transmittances and broader hysteresis loops thanks to the formation of generallylarger grains, although with heterogeneous morphology and size distribution. These same events also causedunwanted increases in the metal-to-insulator transition temperature and the occurrence of asymmetric hysteresisloops. The best performances for smart glazing applications were eventually achieved by instantaneous oxidationof 25 nm thick films deposited with 8 s oxygen pulses, exhibiting remarkable luminous transmittances (>55%),solar modulation abilities (>5%), beneficial drops in critical temperature without doping (up to 7◦C below thestandard value for pure VO2) and an extraordinarily wide variable hysteresis between 18–26◦C. These resultsrepresent a substantial enhancement, mainly regarding visible transmittance and hysteresis width, over thoseattained through similar two-step approaches (atmospheric annealing of vanadium films sputtered at glancingangles), paving the way for further doping processes.
SN 0950-0618
YR 2024
FD 2024-02-20
LK http://hdl.handle.net/10498/32702
UL http://hdl.handle.net/10498/32702
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 05-nov-2026