Fig. 2: Multilayer vs. monolayer bubble geometry.
From: Strong and Localized Luminescence from Interface Bubbles Between Stacked hBN Multilayers
a Schematic of a bubble formed between two multilayers of hBN/hBN on a Si/SiO2 substrate. The radius and height of the bubble are r and h respectively, and the thickness of the top multilayer is t. b The aspect ratio a as a function of the bubble radius r measured from an hBN/hBN multilayer bubble (\(t=70\ {{{{{\rm{nm}}}}}}\), Supplementary Fig. S5). The dashed line indicates the aspect ratio reported previously for hBN monolayer bubbles, which is a constant independent of r26. The shaded region shows the experimentally measured aspect ratio for multilayer bubbles, which is r-dependent and significantly lower than for the monolayer counterpart. Error bars represent one standard deviation above and below the mean. c Experimental deflection profiles experimentally measured from a representative hBN/hBN multilayer bubble (squares) and a hBN/hBN monolayer bubble (circles). The red solid curve fitted to Eq. (1) yields \(\alpha=1.5\). Analytic solutions are also shown for the elastic plate (dashed green line, \(\alpha=2\)) and membrane (dashed blue line, \(\alpha=1\)) models.
