Researchers at City University of Hong Kong, Zhejiang University and The Hong Kong University of Science and Technology have designed a unique triple-layer thermochromic perovskite window (MTPW) that enables sufficient water vapor transmission to trigger the thermochromism but effectively repel detrimental water and moisture to extend its lifespan. The scientists explained they drew inspiration from the structure of medical masks.
Schematic of the trilayer structure and working principle of an antivirus medical mask. b Schematic of the trilayer structure and working principle of the MTPW for repelling water and excess water vapor. Image from Nature Communications
This research addresses the two main challenges hindering the development of thermochromic perovskite smart windows, namely, poor durability and optical blurriness. The MTPW demonstrates superhydrophobicity and maintains a solar modulation ability above 20% during a 45-day aging test, with a decay rate 37 times lower than that of a pristine TPW. It can also immobilize lead ions and significantly reduce lead leakage by 66 times.
Furthermore, a significant haze reduction from 90% to 30% was achieved, overcoming the blurriness problem of TPWs.
Benefiting from the improved optical performance, extended lifespan, suppressed lead leakage, and facile fabrication, the MTPW pushes forward the wide applications of smart windows in green buildings.