Feng Simin, Lin Zhong, Gan Xin, Lv Ruitao, Terrones Mauricio
Department of Physics and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA 16802, USA.
Nanoscale Horiz. 2017 Mar 1;2(2):72-80. doi: 10.1039/c6nh00192k. Epub 2017 Jan 17.
The successful isolation of graphene from graphite in 2004 opened up new avenues to study two-dimensional (2D) systems from layered materials. Since then, research on 2D materials, including graphene, hexagonal-BN (h-BN), transition metal dichalcogenides (TMDs) and black phosphorous, has been extensive, thus leading to various possible applications in the fields of optoelectronics, biomedicine, spintronics, electrochemistry, energy storage and catalysis. However, certain barriers still need to be overcome when dealing with real applications, such as graphene's lack of a bandgap, restricting its use in semiconductor electronics. In this context, a possible solution is to tailor the electronic and optical properties of 2D materials by introducing defects or elemental doping. Although defects play a major role in modifying materials properties, the fact that we call them "defects" might have a negative impact. There has been a long debate on whether structurally perfect materials are equally relevant for modifying the properties and for applications. In this focus article, we clarify that although extra large amounts of defects could be detrimental to the materials properties, well-designed defects might lead to unprecedented properties and interesting applications that pristine materials do not have. Given the relatively short history of research on doped 2D layered materials, our objective is to answer and clarify the following fundamental questions: why does nanomaterial doping offer improved physico-chemical properties? What new applications arise from doping? And what are the current challenges along this line?
2004年从石墨中成功分离出石墨烯，为研究层状材料中的二维（2D）系统开辟了新途径。从那时起，对包括石墨烯、六方氮化硼（h-BN）、过渡金属二硫属化物（TMDs）和黑磷在内的二维材料的研究广泛开展，从而在光电子学、生物医学、自旋电子学、电化学、能量存储和催化等领域产生了各种可能的应用。然而，在实际应用中仍需克服一些障碍，比如石墨烯缺乏带隙，限制了其在半导体电子学中的应用。在这种背景下，一种可能的解决方案是通过引入缺陷或元素掺杂来调整二维材料的电学和光学性质。尽管缺陷在改变材料性能方面起主要作用，但我们称它们为“缺陷”这一事实可能会产生负面影响。关于结构完美的材料在改变性能和应用方面是否同样相关，一直存在长期争论。在这篇重点文章中，我们阐明，虽然大量缺陷可能对材料性能有害，但精心设计的缺陷可能会带来前所未有的性能和原始材料所没有的有趣应用。鉴于掺杂二维层状材料的研究历史相对较短，我们的目标是回答并阐明以下基本问题：为什么纳米材料掺杂能改善物理化学性质？掺杂会带来哪些新应用？以及这方面目前面临哪些挑战？
