Thiruraman Jothi Priyanka, Dar Sidra Abbas, Masih Das Paul, Hassani Nasim, Neek-Amal Mehdi, Keerthi Ashok, Drndić Marija, Radha Boya
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA.
Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Sci Adv. 2020 Dec 18;6(51). doi: 10.1126/sciadv.abc7927. Print 2020 Dec.
Gas flows are often analyzed with the theoretical descriptions formulated over a century ago and constantly challenged by the emerging architectures of narrow channels, slits, and apertures. Here, we report atomic-scale defects in two-dimensional (2D) materials as apertures for gas flows at the ultimate quasi-0D atomic limit. We establish that pristine monolayer tungsten disulfide (WS) membranes act as atomically thin barriers to gas transport. Atomic vacancies from missing tungsten (W) sites are made in freestanding (WS) monolayers by focused ion beam irradiation and characterized using aberration-corrected transmission electron microscopy. WS monolayers with atomic apertures are mechanically sturdy and showed fast helium flow. We propose a simple yet robust method for confirming the formation of atomic apertures over large areas using gas flows, an essential step for pursuing their prospective applications in various domains including molecular separation, single quantum emitters, sensing and monitoring of gases at ultralow concentrations.
气体流动通常采用一个多世纪前形成的理论描述进行分析，并且不断受到新兴的窄通道、狭缝和孔径结构的挑战。在此，我们报告二维（2D）材料中的原子尺度缺陷作为气体在最终准零维原子极限下流动的孔径。我们确定，原始单层二硫化钨（WS）膜作为气体传输的原子级薄屏障。通过聚焦离子束辐照在独立的（WS）单层中制造出因钨（W）位点缺失而产生的原子空位，并使用像差校正透射电子显微镜对其进行表征。具有原子孔径的WS单层机械坚固，并显示出快速的氦气流。我们提出了一种简单而稳健的方法，利用气体流动来确认大面积原子孔径的形成，这是在包括分子分离、单量子发射器、超低浓度气体传感和监测等各个领域追求其潜在应用的关键步骤。
