Lee Hae Yeon, Sarkar Soumya, Reidy Kate, Kumar Abinash, Klein Julian, Watanabe Kenji, Taniguchi Takashi, LeBeau James M, Ross Frances M, Gradečak Silvija
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02141, USA.
Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore, Singapore.
Nat Commun. 2022 Aug 25;13(1):5000. doi: 10.1038/s41467-022-32708-z.
Extraordinary optoelectronic properties of van der Waals (vdW) heterostructures can be tuned via strain caused by mechanical deformation. Here, we demonstrate strong and localized luminescence in the ultraviolet region from interface bubbles between stacked multilayers of hexagonal boron nitride (hBN). Compared to bubbles in stacked monolayers, bubbles formed by stacking vdW multilayers show distinct mechanical behavior. We use this behavior to elucidate radius- and thickness-dependent bubble geometry and the resulting strain across the bubble, from which we establish the thickness-dependent bending rigidity of hBN multilayers. We then utilize the polymeric material confined within the bubbles to modify the bubble geometry under electron beam irradiation, resulting in strong luminescence and formation of optical standing waves. Our results open a route to design and modulate microscopic-scale optical cavities via strain engineering in vdW materials, which we suggest will be relevant to both fundamental mechanical studies and optoelectronic applications.
范德华（vdW）异质结构的非凡光电特性可通过机械变形引起的应变进行调节。在此，我们展示了来自六方氮化硼（hBN）多层堆叠结构界面气泡在紫外区域的强且局域化的发光。与单层堆叠中的气泡相比，由vdW多层堆叠形成的气泡表现出不同的力学行为。我们利用这种行为来阐明与半径和厚度相关的气泡几何形状以及气泡上产生的应变，据此我们确定了hBN多层的厚度依赖性弯曲刚度。然后，我们利用限制在气泡内的聚合物材料在电子束辐照下改变气泡几何形状，从而产生强发光并形成光学驻波。我们的结果开辟了一条通过vdW材料中的应变工程来设计和调制微观尺度光学腔的途径，我们认为这将与基础力学研究和光电应用都相关。
