Zhao Liyuan, Zhang Renyan, Deng Chuyun, Peng Yuanxi, Jiang Tian
State Key Laboratory of High Performance Computing, National University of Defense Technology, Changsha 410073, China.
College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China.
Nanomaterials (Basel). 2019 Jul 31;9(8):1096. doi: 10.3390/nano9081096.
Controllably tuned infrared emissivity has attracted great interest for potential application in adaptive thermal camouflage. In this work, we report a flexible multilayer graphene based infrared device on a porous polyethylene membrane, where the infrared emissivity could be tuned by ionic liquid intercalation. The Fermi level of surface multilayer graphene shifts to a high energy level through ionic liquid intercalation, which blocks electronic transition below the Fermi level. Thus, the optical absorptivity/emissivity of graphene could be controlled by intercalation. Experimentally, the infrared emissivity of surface graphene was found to be tuned from 0.57 to 0.41 after ionic liquid intercalation. Meanwhile, the relative reflectivity R/R of surface graphene increased from 1.0 to 1.15. The strong fluorescence background of Raman spectra, the upshift of the G peak (~23 cm), and the decrease of sheet resistance confirmed the successful intercalation of ionic liquid into the graphene layers. This intercalation control of the infrared emissivity of graphene in this work displays a new way of building an effective thermal camouflage system.
可控调谐的红外发射率因其在自适应热伪装中的潜在应用而备受关注。在这项工作中，我们报道了一种基于多孔聚乙烯膜的柔性多层石墨烯红外器件，其中红外发射率可通过离子液体插层进行调谐。通过离子液体插层，表面多层石墨烯的费米能级转移到高能级，这阻止了费米能级以下的电子跃迁。因此，石墨烯的光吸收率/发射率可通过插层来控制。实验发现，离子液体插层后，表面石墨烯的红外发射率从0.57调谐到0.41。同时，表面石墨烯的相对反射率R/R从1.0增加到1.15。拉曼光谱的强荧光背景、G峰的上移（约23 cm）以及薄层电阻的降低证实了离子液体成功插入石墨烯层。这项工作中对石墨烯红外发射率的这种插层控制展示了构建有效热伪装系统的新方法。
