Stabilizing monolayer nitrides with silicon Transition metal carbides and nitrides are nonlayered materials that in monolayer form have potentially useful electronic and chemical properties. These monolayers are usually made by chemical etching that produces flakes with surface defects that have poor air and water stability. Hong et al. report that introducing silicon during chemical vapor deposition growth of molybdenum nitride passivates the surface and prevents island formation. Centimeter-scale monolayer films of the semiconductor MoSi2N4 form as a MoN2 layer sandwiched by two Si-N bilayers. These layers possess high mechanical strength and ambient stability. Science, this issue p. 670 Addition of silicon during film growth stabilized a molybdenum nitride monolayer by sandwiching it between two Si-N bilayers. Identifying two-dimensional layered materials in the monolayer limit has led to discoveries of numerous new phenomena and unusual properties. We introduced elemental silicon during chemical vapor deposition growth of nonlayered molybdenum nitride to passivate its surface, which enabled the growth of centimeter-scale monolayer films of MoSi2N4. This monolayer was built up by septuple atomic layers of N-Si-N-Mo-N-Si-N, which can be viewed as a MoN2 layer sandwiched between two Si-N bilayers. This material exhibited semiconducting behavior (bandgap ~1.94 electron volts), high strength (~66 gigapascals), and excellent ambient stability. Density functional theory calculations predict a large family of such monolayer structured two-dimensional layered materials, including semiconductors, metals, and magnetic half-metals.

中文翻译：

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层状二维 MoSi2N4 材料的化学气相沉积

用硅稳定单层氮化物 过渡金属碳化物和氮化物是非层状材料，单层形式具有潜在有用的电子和化学性质。这些单层通常是通过化学蚀刻制成的，这种蚀刻会产生具有表面缺陷的薄片，这些薄片具有较差的空气和水稳定性。洪等人。据报道，在氮化钼的化学气相沉积生长过程中引入硅会使表面钝化并防止形成岛。半导体 MoSi2N4 的厘米级单层膜形成为夹在两个 Si-N 双层之间的 MoN2 层。这些层具有高机械强度和环境稳定性。科学，这个问题 p。670 在薄膜生长过程中添加硅通过将氮化钼单层夹在两个 Si-N 双层之间来稳定它。在单层极限中识别二维层状材料导致发现了许多新现象和不寻常的特性。我们在非层状氮化钼的化学气相沉积生长过程中引入了元素硅以钝化其表面，从而实现了厘米级 MoSi2N4 单层膜的生长。该单层由 N-Si-N-Mo-N-Si-N 的七层原子层构成，可以将其视为夹在两个 Si-N 双层之间的 MoN2 层。这种材料表现出半导体特性（带隙~1.94 电子伏特）、高强度（~66 吉帕斯卡）和出色的环境稳定性。密度泛函理论计算预测了一大类这样的单层结构二维层状材料，包括半导体、金属和磁性半金属。