Regulation engineering of surface synthesized graphene nanoribbons

Graphene has attracted great attention since its discovery. However, it is a zero bandgap material, which greatly limits its application in electronic devices. Doping graphene and double-layer graphene can open the graphene bandgap, but these methods have their inherent disadvantages. In order to realize the wide application of graphene optoelectronic devices, the preparation of graphene nanoribbons with limited width is an effective scheme to open its bandgap. In recent years, researchers have developed many methods to prepare graphene nanoribbons, which are mainly divided into two categories: top-down and bottom-up preparation methods.

How to make graphene

The top-down synthesis methods (such as cutting graphene sheets to form graphene nanoribbons, etc.) are not easy to effectively control the width and edge structure of the nanoribbons, which greatly affects their quality. There are also many bottom-up synthesis methods, such as solution synthesis, which is more difficult to directly characterize the edge structure of graphene nanoribbons than graphene nanoribbons synthesized on the surface. Surface synthesized graphene nanoribbons are easy to be prepared and characterized, which is an effective preparation method.

Institute of Chemistry, Chinese Academy of Sciences, comprehensively reviewed the surface synthesis strategies of graphene nanoribbons. This paper expounds on the two elements of preparing graphene nanoribbons: precursors and growth substrates and summarizes that graphene nanoribbons with different structures can be obtained by selecting different precursors and growth substrates. Secondly, the preparation strategies of graphene nanoribbons with different widths, edge structures, and skeleton structures are summarized, mainly involving graphene nanoribbons with armchair, zigzag, chiral, and Chevron structures.

It is shown that the width, edge, and skeleton structure of nanoribbons can be effectively controlled by surface synthesis technology, So as to regulate its internal energy band structure. In addition, the preparation strategies of a variety of heteroatom doped graphene nanoribbons and different types of graphene nanoribbons heterojunction structures are also introduced. These types of nanoribbons can directly regulate the internal electronic structure of graphene nanoribbons at the atomic level. Finally, the preparation and performance characteristics of graphene nanodevices are summarized, which shows that the surface synthesized graphene nanoribbons have relatively good device performance, but there is still room for development in the preparation of nanoribbons and devices.

The researchers believe that the surface synthesis of graphene nanobelt is conducive to promoting the research of graphene-based materials, especially in its optoelectronic devices.