The stability, electronic, mechanical and thermal properties of three novel superhard carbon crystals

A superhard sp2–sp3 hybridized orthorhombic carbon allotrope with conductive property under extreme pressure

“…C co -C 8 (C-centered orthorhombic C 8 ) is an indirect band gap semiconductor having hardness value 95.1 GPa [11]. Similarly, P-carbon [12,13], monoclinic M-carbon [14], W-carbon [15], X-carbon, Y-carbon [16], bet-C4 [17], T-carbon [18,19], Orthorhombic C32 [1], PM1, PM2, PM3 [20], Orthorhombic C20 [21], etc are superhard semiconductors having sp 3 bonding network. Among all these allotropes, T-carbon has been experimentally synthesized in laboratory [19].…”

Zero to Three Dimension Structure Evolution from Carbon Allotropes to Phosphorus Allotropes

“…[1][2][3] The light weight, good thermal and electronic conductivity, high strength, and high stability of carbon nanomaterials triggered the naonscience in electronic, optoelectronic, medicine, mechanical, catalyst, and energy applications. The applications of carbon nanomaterials in electronic devices [4][5][6][7][8][9][10][11][12][13][14] conquered the impediments from silicon-based ones to follow Moor's Law. [15,16] The high conductivity and stability of carbon nanomaterials make them ideal conducting skeletons for electrochemical materials.…”

New stable 2D and 3D GeC2 crystal structures predicted by first-principles study

“…In group IVA of the Periodic Table of the Element, carbon, silicon, and germanium are three important elements for semiconductor materials. In particular, carbon in sp, sp 2 , and sp 3 hybridization, has much flexibility of bonding and exists in tremendous forms of allotropes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15], which exhibit numerous unique physical and chemical properties. These carbon allotropes can be classified into four different groups according to their band gap and mass density, namely (1) wide gap and high density, (2) narrow gap and high density, (3) narrow gap and low density, and (4) wide gap and low density.…”

“…A typical representation in group (1) is the well-studied diamond with a band gap of 5.4 eV and a mass density of 3.54 g/cm 3 [1]. In addition to diamond, many other carbon allotropes in group (1) also have a band gap larger than 3 eV and a mass density higher than 3 g/cm 3 , such as P carbon (3.64 eV and 3.41 g/cm 3 ) [2], h-diamond (3.13 eV and 3.52 g/cm 3 ) [3], M carbon (3.56 eV and 3.45 g/cm 3 ) [4], C10 (4.6 eV and 3.55 g/cm 3 ) [5], 8-tetra (2, 2) (3.76 eV and 3.3 g/cm 3 ) [6,7], PM1, PM2, and PM3 (3.07-3.09 eV and 3.38-3.48 g/cm 3 ) [8], D carbon (4.33 eV and 3.2 g/cm 3 ) [9], and protomene (3.38 eV and 3.5 g/cm 3 ) [10]. An example in group (2) allotrope having a narrow band gap and high density is novamene with a band gap of 0.3 eV and a mass density of 3.4 g/cm 3 [11].…”

“…In addition to the classification of carbon allotropes according to their properties such as band gap and mass density, many literature work also assorts the structures according to their geometrical compositions, such as hexagonal, tetragonal, pentagonal, octagonal, heptagonal carbon rings, and some combinations of the mentioned rings. For example, the following structures show varying geometrical composition of carbon rings, 6-membered rings [3], 4+8 membered rings [2], 4+6+8 membered rings [8], 4+5 membered rings [9], and 5+7 membered rings [2], and so on. In this work, our proposed new 3D carbon structure consists of a unique tetragonal and hexagonal (4+6 membered) carbon rings (named as TH-C), which is constructed on an AB stacking of a recently discovered two-dimensional (2D) monolayer sp 2 -and sp 3 -hybridized carbon allotrope known as tetrahex-C [16].…”