Midinfrared Electro-optic Modulation in Few-Layer Black Phosphorus
Midinfrared Electro-optic Modulation in Few-Layer Black Phosphorus
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DOI：
10.1021/acs.nanolett.7b03050
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发表时间：
2017-10-01
期刊：
影响因子：
10.8
通讯作者：
Li, Mo
中科院分区：
文献类型：
--
作者：
Peng, Ruoming;Khaliji, Kaveh;Li, Mo
黑磷从二维材料家族中脱颖而出，是一种具有直接的、依赖于层的带隙的半导体，跨越可见光到中红外（中红外）光谱范围。因此，它是一种非常有前途的材料，用于各种光电应用，特别是在重要的中红外范围内。虽然中红外技术发展迅速，但中红外的光电探测和电光调制都依赖于窄带化合物半导体，这与无处不在的硅光子学集成起来既困难又昂贵。对于中红外光探测，黑磷已经被证明是一种可行的替代品。在这里，我们展示了电光调制中红外吸收在几层黑磷。我们的实验和理论结果发现，在我们的样品中可获得的掺杂范围内，量子限制的Franz-Keldysh效应是电光调制的主导机制。不同厚度的样品的光谱研究揭示了强烈的层依赖性在特定的子带对之间的带间过渡。我们的研究结果表明，黑磷是一个非常有前途的材料，实现高效的中红外调制器。
Black phosphorus stands out from the family of two-dimensional materials as a semiconductor with a direct, layer-dependent bandgap spanning the visible to mid-infrared (mid-IR) spectral range. It is, therefore, a very promising material for various optoelectronic applications, particularly in the important mid-IR range. While mid-IR technology has been advancing rapidly, both photodetection and electro-optic modulation in the mid-IR rely on narrow-band compound semiconductors, which are difficult and expensive to integrate with the ubiquitous silicon photonics. For mid-IR photo detection, black phosphorus has already been proven to be a viable alternative. Here, we demonstrate electro-optic modulation of mid-IR absorption in few-layer black phosphorus. Our experimental and theoretical results find that, within the doping range obtainable in our samples, the quantum confined Franz-Keldysh effect is the dominant mechanism of electro-optic modulation. A spectroscopic study on samples with varying thicknesses reveals strong layer dependence in the interband transition between specific pairs of sub-bands. Our results show that black phosphorus is a very promising material to realizing efficient mid-IR modulators.