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

近年来，二维材料或1（或几个）原子厚的平面薄片的发现引起了极大的兴奋和研究活动。石墨烯、六方氮化硼（h-BN）和过渡金属二硫族化合物（TMD）获得了最大的关注，并在利用这些材料开发新型电子、光学和能源应用方面取得了进展。二维材料在技术上的实际应用面临两个关键挑战：1)每种材料（如它们的三维同素异形体）都有可能限制其使用的特定特性。例如，由于石墨烯没有带隙，它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（通过计算方法预测了最高的性质），如硅烯、锗烯和磷烯，它们随后以某种方式被合成。2)二维材料不容易大规模生长，对制造工作流程构成集成挑战。许多先锋实验结果的报道是机械剥离的结果。从那时起，在化学气相沉积生长、化学去角质和其他制备方面取得了相当大的进展。然而，对于可替代的二维材料，很少有工作存在。本研究计划的目的是开发一种新颖的、可扩展的方法，利用离子注入来生长可替代的二维材料硅烯、磷烯和锗烯。最近的研究表明，将碳植入铜中，然后进行退火处理，可以在铜表面形成高质量的石墨烯层。本建议打算将此扩展到其他第四组二维材料。在这项研究中，我们将开发1)适当的生长方法来制造硅烯、锗烯和磷烯；2)一个计算和热力学模型来描述离子注入和二维层自组装的化学过程；3)使用透射电子显微镜（TEM）对这些材料的原子、电子和化学结构进行高级表征；4)集成到基线电子设备中。这些发现最终可以为我们深入了解植入化学的基本过程，离子注入制造可扩展的新型二维材料的机制，以及值得进一步研究的有趣新材料。最终，这些新材料的成功生长可能会导致更快、更敏感的电子设备，并且在硅烯和锗烯的情况下，可以集成（与石墨烯相比）到现有的半导体工作流程中。这项研究有可能促进加拿大半导体制造业的商业发展，并培养高素质的科学家。

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.The aim of this research program is to develop a novel, scaleable method to grow the alternative 2-dimensional materials silicene, phosphorene, and germanene using ion implantation. Recent work showed that the implantation of carbon into copper, followed by a subsequent anneal results in the development of a high-quality graphene layer on the copper surface [1]. This proposal intends to extend this to other Group IV 2-D materials. During this study, we will develop 1) appropriate growth methods to fabricate wafer-scale silicene, germanene, and phosphorene, 2) a computational and thermodynamic model that describes the chemistry of ion implantation and self-assembly of 2-D layers and 3) the advanced characterization of the atomic, electronic, and chemical structure of these materials using transmission electron microscopy (TEM) and 4) integration into baseline electronic devices. These findings can ultimately provide us in-depth knowledge of the fundamental processes of implant chemistry, a mechanism for ion implantation to fabricate scaleable novel 2-D materials, and interesting new materials for further study. Ultimately, successful growth of these new materials could lead to faster and more sensitive electronic devices and, in the case of silicene and germanene, could be integrated (as compared to graphene) into already-existing semiconductor workflows. There is potential to for commercial advances in the Canadian semiconductor manufacturing sector and for training high quality scientists as a result of this research.