Control of two-dimensional excitonic light emission via photonic crystal
Control of two-dimensional excitonic light emission via photonic crystal
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DOI：
10.1088/2053-1583/1/1/011001
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发表时间：
2014-06-01
期刊：
影响因子：
5.5
通讯作者：
Xu, Xiaodong
中科院分区：
文献类型：
--
作者：
Wu, Sanfeng;Buckley, Sonia;Xu, Xiaodong
过渡金属二硫属化合物（TMDCs）单分子膜是一种新型的二维光电子材料，具有丰富的自旋-谷相互作用、可调激子效应和强的光-物质相互作用。许多光子应用的一个重要但尚未开发的成分是操纵其光发射。在这里，我们展示了激子光发射的控制单层二硒化钨（WSe 2）在一个集成的光子结构，实现了通过转移一个单层到光子晶体（PhC）与腔。除了观察到有效耦合的腔模式发射，悬浮效应对PhC不仅导致大大增强（类似于60倍）的光致发光，而且还强烈图案的发射在亚波长空间尺度，对比开和关的孔。这样的效果导致一个显着的衍射光栅效应，这使我们能够重新分配发射的光子的极性和方位角在远场通过设计光子晶体结构，如动量分辨显微镜所揭示的。由此构造了2D光学天线。我们的工作提出了一种在混合2D光子学中操纵光子的新方法，这对未来节能光电子学和2D纳米激光器很重要。
Monolayers of transition metal dichalcogenides (TMDCs) have emerged as new optoelectronic materials in the two dimensional (2D) limit, exhibiting rich spin-valley interplays, tunable excitonic effects, and strong light-matter interactions. An essential yet undeveloped ingredient for many photonic applications is the manipulation of its light emission. Here we demonstrate the control of excitonic light emission from monolayer tungsten diselenide (WSe2) in an integrated photonic structure, achieved by transferring one monolayer onto a photonic crystal (PhC) with a cavity. In addition to the observation of an effectively coupled cavity-mode emission, the suspension effects on PhC not only result in a greatly enhanced (similar to 60 times) photoluminescence but also strongly pattern the emission in the subwavelength spatial scale, contrasting on and off the holes. Such an effect leads to a significant diffraction grating effect, which allows us to redistribute the emitted photons both polarly and azimuthally in the far field through designing PhC structures, as revealed by momentum-resolved microscopy. A 2D optical antenna is thus constructed. Our work suggests a new way of manipulating photons in hybrid 2D photonics, important for future energy efficient optoelectronics and 2D nano-lasers.