Electrochromic(EC)materials that change color with voltage have been widely studied for use in dynamic windows.However,colorless-to-colorful switching with high contrast ratio is generically unattainable,especially fo...Electrochromic(EC)materials that change color with voltage have been widely studied for use in dynamic windows.However,colorless-to-colorful switching with high contrast ratio is generically unattainable,especially for colorless-to-black electrochromic materials with an ultrahigh contrast ratio over the entire visible region.In this work,we developed Nb_(1.33)C MXene-based dynamic windows with colorless-to-black switching of up to 75%reversible change in transmittance from 300 to 1,500 nm.By exploring the electrochromic effects of different electrolytes through in situ optical changes and electrochemical quartz crystal microbalance(EQCM),it is found that electrochromic behavior is greatly influenced by the extent of reversible Li^(+)insertion/deinsertion between the two-dimensional Nb_(1.33)C MXene nanosheets.In addition,a colorless-to-black EC device based on Nb_(1.33)C with an overall integrated contrast ratio over 80%was successfully constructed by a solution-processable spin coating method.This work enables a simple route to fabricate MXene-based high-performance electrochromic smart windows,which is important for further expanding the application of MXenes to optoelectronic and photonic applications.展开更多
基金This work was financed by the SSF Research Infrastructure Fellow Program(No.RIF 14–0074)the SSF Synergy Program EM16–0004,and by the Knut and Alice Wallenberg(KAW)Foundation through a Fellowship Grant,a Project Grant(No.KAW2020.0033)+4 种基金for support of the electron microscopy laboratory in Linköping University.Support from the National Natural Science Foundation of China(No.61774077)the Guangdong Joint Research Fund(No.2020A1515110738)the Postdoctoral Research Foundation of China(No.2020M683187)the Key Projects of Joint Fund of Basic and Applied Basic Research Fund of Guangdong Province(No.2019B1515120073)the Guangzhou Key laboratory of Vacuum Coating Technologies and New Energy Materials Open Projects Fund(No.KFVE20200006)are also acknowledged.
文摘Electrochromic(EC)materials that change color with voltage have been widely studied for use in dynamic windows.However,colorless-to-colorful switching with high contrast ratio is generically unattainable,especially for colorless-to-black electrochromic materials with an ultrahigh contrast ratio over the entire visible region.In this work,we developed Nb_(1.33)C MXene-based dynamic windows with colorless-to-black switching of up to 75%reversible change in transmittance from 300 to 1,500 nm.By exploring the electrochromic effects of different electrolytes through in situ optical changes and electrochemical quartz crystal microbalance(EQCM),it is found that electrochromic behavior is greatly influenced by the extent of reversible Li^(+)insertion/deinsertion between the two-dimensional Nb_(1.33)C MXene nanosheets.In addition,a colorless-to-black EC device based on Nb_(1.33)C with an overall integrated contrast ratio over 80%was successfully constructed by a solution-processable spin coating method.This work enables a simple route to fabricate MXene-based high-performance electrochromic smart windows,which is important for further expanding the application of MXenes to optoelectronic and photonic applications.