Giant two-photon absorption in bilayer graphene.
Giant two-photon absorption in bilayer graphene.
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DOI：
10.1021/nl200587h
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发表时间：
2011-06
期刊：
影响因子：
10.8
通讯作者：
Hongzhi Yang;Xiaobo Feng;Qian Wang;Han Huang;Wei Chen;A. Wee;W. Ji
中科院分区：
文献类型：
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作者：
Hongzhi Yang;Xiaobo Feng;Qian Wang;Han Huang;Wei Chen;A. Wee;W. Ji
本文提出了一种研究单层和双层Bernal堆叠石墨烯双光子吸收的量子微扰理论。该理论表明，在可见光和红外光谱（高达3 μm）中，双层石墨烯中的2 PA明显大于单层石墨烯，其中共振2 PA系数高达0.2 cm/W，位于带隙能量的一半，γ（1）= 0.4 eV。在可见光和太赫兹波段，2 PA在双层石墨烯中表现出ω（-3）的光频率依赖性，而在所有光子能量下，2 PA在单层石墨烯中与ω（-4）成比例。在同一数量级内，2 PA理论与我们在780和1100 nm光波长下对沉积在SiC衬底上的高质量外延双层石墨烯的Z扫描测量结果一致。
We present a quantum perturbation theory on two-photon absorption (2PA) in monolayer and bilayer graphene which is Bernal-stacked. The theory shows that 2PA is significantly greater in bilayer graphene than monolayer graphene in the visible and infrared spectrum (up to 3 μm) with a resonant 2PA coefficient of up to ∼0.2 cm/W located at half of the bandgap energy, γ(1) = 0.4 eV. In the visible and terahertz region, 2PA exhibits a light frequency dependence of ω(-3) in bilayer graphene, while it is proportional to ω(-4) for monolayer graphene at all photon energies. Within the same order of magnitude, the 2PA theory is in agreement with our Z-scan measurements on high-quality epitaxial bilayer graphene deposited on SiC substrate at light wavelength of 780 and 1100 nm.