Gate-tunable modulation of the optical properties of multilayer graphene by the reversible intercalation of ionic liquid anions
Gate-tunable modulation of the optical properties of multilayer graphene by the reversible intercalation of ionic liquid anions
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DOI：
10.1063/5.0093651
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发表时间：
2022-09-07
影响因子：
3.2
通讯作者：
Cronin, Stephen B. B.
中科院分区：
文献类型：
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作者：
Cai, Zhi;Aravind, Indu;Cronin, Stephen B. B.
我们证明了一个基本的调制的多层石墨烯（类似于100层）的光学性质，使用一个简单的设备组成的多层石墨烯/聚合物电解质膜/金膜堆叠。施加3- 4V的电压驱动阴离子[TFSI]（-）[离子液体二乙基甲基（2-甲氧基乙基）铵双（三氟甲基磺酰基）酰亚胺[DEME] [TFSI]]的嵌入，导致这种光学致密材料的性质的可逆调制。在插入时，我们观察到在G带拉曼模式中的35 cm（-1）的突然移动，在1.67至5 μ m（2000-6000 cm（-1））的波长范围内FTIR反射率的突然增加，以及在石墨烯的拉曼光谱中观察到的发光背景的突然增加。这种材料的光学性质的所有这些突变都是由TFSI-离子的嵌入和自由载流子密度的相关变化（Δ n = 10（20）cm（-3））引起的。在3 V附近观察到的2D带拉曼模式的抑制对应于双共振拉曼过程的泡利阻塞，并且指示Δ E-F = 1.1 eV的费米能量的调制。由AIP Publishing独家授权出版。
We demonstrate a substantial modulation of the optical properties of multilayer graphene (similar to 100 layers) using a simple device consisting of a multilayer graphene/polymer electrolyte membrane/gold film stack. Applying a voltage of 3-4 V drives the intercalation of anion [TFSI](-) [ion liquid diethylmethyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide [DEME] [TFSI]] resulting in the reversible modulation of the properties of this optically dense material. Upon intercalation, we observe an abrupt shift of 35 cm(-1) in the G band Raman mode, an abrupt increase in FTIR reflectance over the wavelength range from 1.67 to 5 mu m (2000-6000 cm(-1)), and an abrupt increase in luminescent background observed in the Raman spectra of graphene. All of these abrupt changes in the optical properties of this material arise from the intercalation of the TFSI- ion and the associated change in the free carrier density (Delta n = 10(20) cm(-3)). Suppression of the 2D band Raman mode observed around 3 V corresponds to Pauli blocking of the double resonance Raman process and indicates a modulation of the Fermi energy of Delta E-F = 1.1 eV. Published under an exclusive license by AIP Publishing.