A new carbon allotrope with high carrier mobility and optical absorption†

Carbon atom has different bonding modes, which provides the possibility for the existence of multilayer carbon allotropes. Among these bonding modes, the sp³ hybrid bonding mode often causes atoms to be noncoplanar. This provides the possibility for the emergence of two-dimensional (2D) multilayer materials. In this work, a new 2D multilayer carbon allotrope named trilaminar buckled T-graphene is proposed. Carbon atoms have sp² and sp³ hybridization in this structure. It is nonmagnetic and has an indirect band gap of 1.70 eV. It has mechanical stability and dynamic stability, and formation energy calculations also prove that it is stable. Thermal stability calculations results indicate that it does not change the bonding pattern at 1000 K. It is an elastically soft material with a low value of elastic constants. This structure shows amazing electrical properties, which has a high hole mobility of close to 3071 cm² V⁻¹ s⁻¹. Optical property calculations results show that it has an optical gap of 1.70 eV and an ultrahigh absorption in visible and near ultraviolet light. Considering all its properties, this structure has great application potential in high-speed electronic and optoelectronic devices, optical filters, modified substrates, and adsorption sensors.