The structure, electromagnetic and optical properties of the O-terminated graphene nanorib- bons with armchair edge are studied using first-principles theory. The results show that the O-terminated armchair edge are m...The structure, electromagnetic and optical properties of the O-terminated graphene nanorib- bons with armchair edge are studied using first-principles theory. The results show that the O-terminated armchair edge are more stable than the H-terminated ribbons and show metal- lic character. Spin-polarized calculations reveal that the antiferromagnetic state are more stable than the ferromagnetic state. The energy band and density of states analyses show that the O-terminated armchair edge are antiferromagnetic semiconductors. Because of the terminated 0 atoms, the dielectric function has an evident red shift and the first peak is the strongest with its main contribution derived from the highest valence band. The peaks of the dielectric function, reflection, absorption, energy loss are related to the transition of electrons. Our results suggest that the O-terminated graphene nanoribbons have potential applications in nanoelectronics, opto-electric devices.展开更多
The optical properties of F- and H-terminated silicon nanoribbons with armchair edges（F- and H- terminated ASi NRs）are compared by using the first-principles within the density function theory（DFT） framework. The ...The optical properties of F- and H-terminated silicon nanoribbons with armchair edges（F- and H- terminated ASi NRs）are compared by using the first-principles within the density function theory（DFT） framework. The results show that compared with for H-terminated 7-ASi NR, the dielectric function for the F-terminated 7-ASi NR has a red shift, which is mainly attributed to the narrower band gap because of the σ–π mixing effect of F–Si bonds in F-terminated 7-ASi NR.The peaks in the energy loss spectra for both systems represent the characteristics associated with the plasma resonance,which correspond to the trailing edges in the reflection spectra. These properties show that the different terminated atoms in7-ASi NRs affect mainly the optical properties in the low energy range. Because of the rich optical properties, the 7-ASi NR could be a potential candidate for photoelectric nanodevice.展开更多
文摘The structure, electromagnetic and optical properties of the O-terminated graphene nanorib- bons with armchair edge are studied using first-principles theory. The results show that the O-terminated armchair edge are more stable than the H-terminated ribbons and show metal- lic character. Spin-polarized calculations reveal that the antiferromagnetic state are more stable than the ferromagnetic state. The energy band and density of states analyses show that the O-terminated armchair edge are antiferromagnetic semiconductors. Because of the terminated 0 atoms, the dielectric function has an evident red shift and the first peak is the strongest with its main contribution derived from the highest valence band. The peaks of the dielectric function, reflection, absorption, energy loss are related to the transition of electrons. Our results suggest that the O-terminated graphene nanoribbons have potential applications in nanoelectronics, opto-electric devices.
基金Project supported by the Henan Provincial Joint Funds of the National Natural Science Foundation of China(Grant Nos.U1404608 and U1304612)the Science and Technology Key Projects of Henan Province+2 种基金China(Grant No.1502102210124)the Special Fund for Theoretical Science Foundation of Nanyang Normal UniversityChina(Grant No.ZX2013018)
文摘The optical properties of F- and H-terminated silicon nanoribbons with armchair edges（F- and H- terminated ASi NRs）are compared by using the first-principles within the density function theory（DFT） framework. The results show that compared with for H-terminated 7-ASi NR, the dielectric function for the F-terminated 7-ASi NR has a red shift, which is mainly attributed to the narrower band gap because of the σ–π mixing effect of F–Si bonds in F-terminated 7-ASi NR.The peaks in the energy loss spectra for both systems represent the characteristics associated with the plasma resonance,which correspond to the trailing edges in the reflection spectra. These properties show that the different terminated atoms in7-ASi NRs affect mainly the optical properties in the low energy range. Because of the rich optical properties, the 7-ASi NR could be a potential candidate for photoelectric nanodevice.
