Efficient light generation from enhanced inelastic electron tunnelling
Efficient light generation from enhanced inelastic electron tunnelling
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DOI：
10.1038/s41566-018-0216-2
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发表时间：
2018-08-01
期刊：
影响因子：
35
通讯作者：
Liu, Zhaowei
中科院分区：
文献类型：
--
作者：
Qian, Haoliang;Hsu, Su-Wen;Liu, Zhaowei
偏置隧道结的光发射由于其独特的潜力而获得了广泛的关注，以创建具有太赫兹调制带宽（1-5）的超紧凑光源。发射起源于非弹性电子隧穿过程，其中电子能量被转移到表面等离子体激元，随后通过光学天线转换为辐射光子。因为大多数电子弹性隧穿，所以发射效率通常约为10（-5）-10（-4）。在这里，我们展示了高效的光产生增强的非弹性隧穿使用纳米晶体组装成金属-绝缘体-金属结。发射光的颜色由光学天线确定，因此可以通过结结构的几何形状进行调谐。远场自由空间光产生的效率达到接近2%，比之前的工作提高了两个数量级（3，4）。这使片上超快和超紧凑光源离现实又近了一步。
Light emission from biased tunnel junctions has recently gained much attention owing to its unique potential to create ultracompact optical sources with terahertz modulation bandwidth(1-5). The emission originates from an inelastic electron tunnelling process in which electronic energy is transferred to surface plasmon polaritons and subsequently converted to radiation photons by an optical antenna. Because most of the electrons tunnel elastically, the emission efficiency is typically about 10(-5)-10(-4). Here, we demonstrate efficient light generation from enhanced inelastic tunnelling using nanocrystals assembled into metal-insulator-metal junctions. The colour of the emitted light is determined by the optical antenna and thus can be tuned by the geometry of the junction structures. The efficiency of far-field free-space light generation reaches similar to 2%, showing an improvement of two orders of magnitude over previous work(3,4). This brings on-chip ultrafast and ultracompact light sources one step closer to reality.