Optical materials with colour changing abilities have been explored for use in display devices¹, smart windows^2,3 or in the modulation of visual appearance^4,5,6. 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.

具有变色能力的光学材料已被探索用于显示设备¹、智能窗口^2,3或视觉外观调制^4,5,6. 然而，这些材料的效率具有很强的波长依赖性，这将它们的功能限制在特定的光谱范围内。在这里，我们报告了基于石墨烯的电光器件，其具有前所未有的光学可调性，覆盖了从可见光到微波的整个电磁光谱。我们通过在光学可访问的器件结构中将锂电嵌入石墨烯层中来实现这种非易失性和可逆的可调性。独特的颜色变化能力，以及区域选择性插层，激发了新型多光谱设备的制造，包括显示设备和电光伪装涂层。