Photonics / Fotonik
Permanent URI for this collectionhttps://hdl.handle.net/11147/2590
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Article Citation - WoS: 40Citation - Scopus: 38Gas Permeation Through Graphdiyne-Based Nanoporous Membranes(Nature Research, 2022) Zhou, Zhihua; Tan, Yongtao; Yang, Qian; Bera, Achintya; Xiong, Zecheng; Yağmurcukardeş, Mehmet; Kim, MinsooNanoporous membranes based on two dimensional materials are predicted to provide highly selective gas transport in combination with extreme permeance. Here we investigate membranes made from multilayer graphdiyne, a graphene-like crystal with a larger unit cell. Despite being nearly a hundred of nanometers thick, the membranes allow fast, Knudsen-type permeation of light gases such as helium and hydrogen whereas heavy noble gases like xenon exhibit strongly suppressed flows. Using isotope and cryogenic temperature measurements, the seemingly conflicting characteristics are explained by a high density of straight-through holes (direct porosity of ∼0.1%), in which heavy atoms are adsorbed on the walls, partially blocking Knudsen flows. Our work offers important insights into intricate transport mechanisms playing a role at nanoscale.Article Citation - WoS: 192Citation - Scopus: 194Multispectral Graphene-Based Electro-Optical Surfaces With Reversible Tunability From Visible To Microwave Wavelengths(Nature Research, 2021) Ergoktas, M. Said; Bakan, Gökhan; Kovalska, Evgeniya; Le Fevre, Lewis W.; Fields, Richard P.; Steiner, Pietro; Yu, Xiaoxiao; Balcı, SinanOptical materials with colour changing abilities have been explored for use in display devices(1), smart windows(2,3) or in the modulation of visual appearance(4-6). The efficiency of these materials, however, has strong wavelength dependence, which limits their functionality to a specific spectral range. Here, we report graphene-based electro-optical devices with unprecedented optical tunability covering the entire electromagnetic spectrum from the visible to microwave. We achieve this non-volatile and reversible tunability by electro-intercalation of lithium into graphene layers in an optically accessible device structure. The unique colour changing capability, together with area-selective intercalation, inspires the fabrication of new multispectral devices, including display devices and electro-optical camouflage coating. We anticipate that these results provide realistic approaches for programmable smart optical surfaces with a potential utility in many scientific and engineering fields such as active plasmonics and adaptive thermal management.