Effect of Si and Ge Surface Doping on the Be2C Monolayer: Case Study on Electrical and Optical Properties

The electronic and optical properties of X (Si, Ge) doped Be2C monolayer has been investigated using the all-electron full potential linear augmented plane wave (FP-LAPW+lo) method in a scalar relativistic version as embodied in the Wien2k code based on the density functional theory. Using cohesive energy calculation, it has been shown that the Si and Ge doped to Be2C monolayer have stable structures and the doping processes modified the direct band gaps. The calculated electronic band structure confirm the direct band gap nature since the conduction band minimum and the valence band maximum are located at the center of the Brillouin zone. The total and partial density of states help to gain further information regarding the hybridizations and the orbitals which control the energy band gap. The calculated optical properties help to gain deep insight into the electronic structure. Our calculated results indicate that the X (Si, Ge) doped Be2C monolayer can be have potential application in optoelectronics devices

Graphene Supported Graphene/Graphane Bilayer Nanostructure Material for Spintronics

[[abstract]]We report an investigation into the magnetic and electronic properties of partially hydrogenated vertically aligned few layers graphene (FLG) synthesized by microwave plasma enhanced chemical vapor deposition. The FLG samples are hydrogenated at different substrate temperatures to alter the degree of hydrogenation and their depth profile. The unique morphology of the structure gives rise to a unique geometry in which graphane/graphone is supported by graphene layers in the bulk, which is very different from other widely studied structures such as one-dimensional nanoribbons. Synchrotron based x-ray absorption fine structure spectroscopy measurements have been used to investigate the electronic structure and the underlying hydrogenation mechanism responsible for the magnetic properties. While ferromagnetic interactions seem to be predominant, the presence of antiferromagnetic interaction was also observed. Free spins available via the conversion of sp2 to sp3 hybridized structures, and the possibility of unpaired electrons from defects induced upon hydrogenation are thought to be likely mechanisms for the observed ferromagnetic orders.[[notice]]補正完