Nano-imaging of intersubband transitions in van der Waals quantum wells
Nano-imaging of intersubband transitions in van der Waals quantum wells
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DOI：
10.1038/s41565-018-0233-9
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发表时间：
2018-06
影响因子：
38.3
通讯作者：
P. Schmidt;F. Vialla;S. Latini;M. Massicotte;Klaas-Jan Tielrooij;S. Mastel;G. Navickaite;M. Danovich;D. Ruiz-Tijerina;C. Yelgel;V. Fal’ko;K. Thygesen;R. Hillenbrand;F. Koppens
中科院分区：
文献类型：
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作者：
P. Schmidt;F. Vialla;S. Latini;M. Massicotte;Klaas-Jan Tielrooij;S. Mastel;G. Navickaite;M. Danovich;D. Ruiz-Tijerina;C. Yelgel;V. Fal’ko;K. Thygesen;R. Hillenbrand;F. Koppens
几十年来，半导体异质结构的发展推动了电子学和光电子学的科学和应用。红外和太赫兹频率范围的许多应用利用了半导体量子阱中量子态之间的跃迁(子带间跃迁)。然而，由于扩散界面和晶格匹配生长条件的要求，目前的量子阱器件在功能和通用性方面受到限制。在这里，我们引入了范德华量子阱中的子带间跃迁的概念，并首次报道了它们的实验观测结果。范德华量子阱是由二维材料自然形成的，具有克服上述限制的未知潜力-它们形成原子尖锐的界面，可以很容易地结合成异质结构，而不受晶格匹配的限制。我们使用近场局域探测来以纳米级的空间分辨率光谱解析子带间跃迁，并通过静电控制吸收。这项工作使开发具有无与伦比的设计自由度的子带间跃迁以及适用于光电探测器、发光二极管和激光器的单独的电子和光学控制成为可能。
The science and applications of electronics and optoelectronics have been driven for decades by progress in the growth of semiconducting heterostructures. Many applications in the infrared and terahertz frequency range exploit transitions between quantized states in semiconductor quantum wells (intersubband transitions). However, current quantum well devices are limited in functionality and versatility by diffusive interfaces and the requirement of lattice-matched growth conditions. Here, we introduce the concept of intersubband transitions in van der Waals quantum wells and report their first experimental observation. Van der Waals quantum wells are naturally formed by two-dimensional materials and hold unexplored potential to overcome the aforementioned limitations—they form atomically sharp interfaces and can easily be combined into heterostructures without lattice-matching restrictions. We employ near-field local probing to spectrally resolve intersubband transitions with a nanometre-scale spatial resolution and electrostatically control the absorption. This work enables the exploitation of intersubband transitions with unmatched design freedom and individual electronic and optical control suitable for photodetectors, light-emitting diodes and lasers.