High Performance and Enhanced Durability of Thermochromic Films Using VO₂@ZnO Core–Shell Nanoparticles

For VO₂-based thermochromic smart windows, high luminous transmittance (<i>T</i>_lum) and solar regulation efficiency (Δ<i>T</i>_sol) are usually pursued as the most critical issues, which have been discussed in numerous researches. However, environmental durability, which has rarely been considered, is also so vital for practical application because it determines lifetime and cycle times of smart windows. In this paper, we report novel VO₂@ZnO core–shell nanoparticles with ultrahigh durability as well as improved thermochromic performance. The VO₂@ZnO nanoparticles-based thermochromic film exhibits a robust durability that the Δ<i>T</i>_sol keeps 77% (from 19.1% to 14.7%) after 10³ hours in a hyperthermal and humid environment, while a relevant property of uncoated VO₂ nanoparticles-based film badly deteriorates after 30 h. Meanwhile, compared with the uncoated VO₂-based film, the VO₂@ZnO-based film demonstrates an 11.0% increase (from 17.2% to 19.1%) in Δ<i>T</i>_sol and a 31.1% increase (from 38.9% to 51.0%) in <i>T</i>_lum. Such integrated thermochromic performance expresses good potential for practical application of VO₂-based smart windows

Achieving High Current Density of Perovskite Solar Cells by Modulating the Dominated Facets of Room-Temperature DC Magnetron Sputtered TiO₂ Electron Extraction Layer

The short circuit current density of perovskite solar cell (PSC) was boosted by modulating the dominated plane facets of TiO₂ electron transport layer (ETL). Under optimized condition, TiO₂ with dominant {001} facets showed (i) low incident light loss, (ii) highly smooth surface and excellent wettability for precursor solution, (iii) efficient electron extraction, and (iv) high conductivity in perovskite photovoltaic application. A current density of 24.19 mA cm^–2 was achieved as a value near the maximum limit. The power conversion efficiency was improved to 17.25%, which was the record value of PSCs with DC magnetron sputtered carrier transport layer. What is more, the room-temperature process had a great significance for the cost reduction and flexible application of PSCs

Composite Film of Vanadium Dioxide Nanoparticles and Ionic Liquid–Nickel–Chlorine Complexes with Excellent Visible Thermochromic Performance

Vanadium dioxide (VO₂), as a typical thermochromic material used in smart windows, is always limited by its weaker solar regulation efficiency (Δ<i>T</i>_sol) and lower luminous transmittance (<i>T</i>_lum). Except for common approaches such as doping, coating, and special structure, compositing is another effective method. The macroscopic thermochromic (from colorless to blue) ionic liquid–nickel–chlorine (IL–Ni–Cl) complexes are selected in this paper to be combined with VO₂ nanoparticles forming a composite film. This novel scheme demonstrates outstanding optical properties: Δ<i>T</i>_sol = 26.45% and <i>T</i>_lum,l = 66.44%, <i>T</i>_lum,h = 43.93%. Besides, the addition of the IL–Ni–Cl complexes endows the film with an obvious color change from light brown to dark green as temperature rises. This splendid visible thermochromic performance makes the composite film superior in function exhibiting and application of smart windows