By comparing the available data, it was found that the band gaps obey the same pattern of change. Here, n A represents the number of armchair chains in graphene, whereas N A represents the number of carbon columns in graphene, that is, n A = 2 N A. This is because different parameters have been used. This result is similar to that of graphene nanoroads in BN sheets, but it may seem different from the band gap hierarchy in : Δ E 3 q > Δ E 3 q + 1 > Δ E 3 q + 2, where N A = 3q, 3q + 1 and 3q + 2, and q is a positive integer. At larger sizes (p > 2), the gap size hierarchy is changed to Δ E 3 p > Δ E 3 p + 2 > Δ E 3 p + 1. At smaller sizes (p ≤ 2), there is a hierarchy of gap size: Δ E 3 p > Δ E 3 p + 1 > Δ E 3 p + 2. Therefore, the band gap behavior can be divided into three cases, n A = 3p, 3p + 1 and 3p + 2, where p is a positive integer. Īs shown in Figure 4, the band gaps of (8, n A) BN/AGNRs have an oscillatory behavior with period p = 3. Both of them have been shown to have band gaps. There are two different groups of GNRs, categorized according to the edge termination types, i.e., zigzag and armchair GNRs. Cutting graphene in specific patterns can form graphene nanoribbons (GNRs), quasi-one-dimensional graphene nanostructures, which can exhibit either quasi-metallic or semiconducting behavior, depending on their specific chirality, including width, lattice orientation and edge geometry. Nitrogen doping is one of the most popular chemical modifications of graphene, as it has great potential for applications, ranging from supercapacitors, to fuel cells, to hydrogen storage materials. Graphene can be chemically modified by heteroatom insertion to modulate its photoelectric properties or chemical activity. Although graphene has many excellent properties, the characteristic of zero band gap limits its application in the semiconductor industry. Its unique composition and electronic energy bands give graphene a series of attractive physical properties, such as high carrier mobility, atomic thinness and linear dispersion. Since its discovery in 2004, graphene has become a research field of tremendous interest, and has also led to the rise in two-dimensional materials.
0 Comments
Leave a Reply. |