Beyond Graphene - Design, Growth, and Characterization of Alternative 2-Dimensional Materials

近年来，二维材料，即一个(或几个)原子(S)厚度的平面片的发现，引起了巨大的兴奋和研究活动。石墨烯、六方氮化硼(h-BN)和过渡金属二卤化物(TMD)引起了人们极大的关注，这些材料在开发新的电子、光学和能源应用方面取得了进展。2-D材料在技术上的实际应用面临两个关键挑战：1)每种材料(就像它们的3-D同素异形体一样)具有可能限制其使用的特定性质。例如，由于石墨烯没有带隙，其在电子设备中的传感或开关应用受到限制。这导致了对替代二维材料的初步研究(通过计算方法预测出了最高的性能)，如硅烯、锗和磷烯，这些材料随后以某种方式合成。2)2-D材料不容易大规模生长，对制造工作流构成集成挑战。报道的许多先锋实验结果都是机械剥离的结果。从那时起，在化学气相沉积生长、化学剥离和其他制备方面取得了相当大的进展。然而，对于替代的2-D材料，几乎没有工作要做。

The discovery of two-dimensional materials, or planar sheets that are 1 (or several) atom(s) thick, in recent years has generated tremendous excitement and research activity. Graphene, hexagonal boron nitride (h-BN), and transition metal dichalcogenides (TMD's) have garnered the lion share of attention and progress has been made in the development of novel electronic, optical and energy applications with these materials. 2-D materials face two critical challenges for their practical use in technology: 1) Each material (like their 3-D allotropes) has specific properties that may limit their use. For example, since graphene does not have a band gap, its use is limited for sensing or switching applications in electronic devices. This has led to nascent work (with superlative properties predicted by computational methods) on alternative 2-D materials, like silicene, germanene and phosphorene, which have been subsequently synthesized in some manner. 2) 2-D materials are not easy to grow at large scale and pose integration challenges for manufacturing workflows. Many of the vanguard experimental results reported on were the result of mechanical exfoliation. Since then, considerable advances in chemical-vapor deposition growth, chemical exfoliation, and other preparations have been developed. However, for alternative 2-D materials, very little work exits.