Quantum interference plays an important role in tuning the transport property of nano-devices. Using the non- equilibrium Green＇s Function method in combination with density functional theory, we investigate the infl...Quantum interference plays an important role in tuning the transport property of nano-devices. Using the non- equilibrium Green＇s Function method in combination with density functional theory, we investigate the influence to the transport property of a CO molecule adsorbed on one edge of a zigzag graphene nanoribbon device. Our results show that the CO molecule-adsorbed zigzag graphene nanoribbon devices can exhibit the Fano resonance phenomenon. Moreover, the distance between CO molecules and zigzag graphene nanoribbons is closely related to the energy sites of the Fano resonance. Our theoretical analyses indicate that the Fano resonance would be attributed to the interaction between CO molecules and the edge of the zigzag graphene nanoribbon device, which results in the localization of electrons and significantly changes the transmission spectrum.展开更多
A pyridine-anchor co-adsorbent of N,N＇-bis（（pyridin-2-yl）（methyl） methylene）-o-phenylenediamine（named BPPI） is prepared and employed as co-adsorbent in dye-sensitized solar cells（DSSCs）. The prepared co-ads...A pyridine-anchor co-adsorbent of N,N＇-bis（（pyridin-2-yl）（methyl） methylene）-o-phenylenediamine（named BPPI） is prepared and employed as co-adsorbent in dye-sensitized solar cells（DSSCs）. The prepared co-adsorbent could overcome the deficiency of N719 absorption in the low wavelength region of visible spectrum, offset competitive visible light absorption of I_3^-, enhance the spectral responses of the co-adsorbed TiO_2 film in region from 300 nm to 750 nm, suppress charge recombination, prolong electron lifetime, and decrease the total resistance of DSSCs. The optimized cell device co-sensitized by BPPI/N719 dye gives a short circuit current density of 12.98 m A cm^（-2）, an open circuit voltage of 0.73 V,and a fill factor of 0.66 corresponding to an overall conversion efficiency of 6.22% under standard global AM 1.5 solar irradiation, which is much higher than that of device solely sensitized by N719（5.29%）under the same conditions. Mechanistic investigations are carried out by various spectral and electrochemical characterizations.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 21673296the Science and technology Plan of Hunan Province under Grant No 2015RS4002the Hunan Provincial Natural Science Foundation under Grant No 2017JJ3063
文摘Quantum interference plays an important role in tuning the transport property of nano-devices. Using the non- equilibrium Green＇s Function method in combination with density functional theory, we investigate the influence to the transport property of a CO molecule adsorbed on one edge of a zigzag graphene nanoribbon device. Our results show that the CO molecule-adsorbed zigzag graphene nanoribbon devices can exhibit the Fano resonance phenomenon. Moreover, the distance between CO molecules and zigzag graphene nanoribbons is closely related to the energy sites of the Fano resonance. Our theoretical analyses indicate that the Fano resonance would be attributed to the interaction between CO molecules and the edge of the zigzag graphene nanoribbon device, which results in the localization of electrons and significantly changes the transmission spectrum.
基金supported by National Natural Science Foundation of China (Nos. 21171044 and 21371040)the National Key Basic Research Program of China (973 Program, No. 2013CB632900)+1 种基金the Fundamental Research Funds for the Central Universities (No. HIT. IBRSEM. A201409)Program for Innovation Research of Science in Harbin Institute of Technology (PIRS of HIT Nos. A201418, A201416 and B201414)
文摘A pyridine-anchor co-adsorbent of N,N＇-bis（（pyridin-2-yl）（methyl） methylene）-o-phenylenediamine（named BPPI） is prepared and employed as co-adsorbent in dye-sensitized solar cells（DSSCs）. The prepared co-adsorbent could overcome the deficiency of N719 absorption in the low wavelength region of visible spectrum, offset competitive visible light absorption of I_3^-, enhance the spectral responses of the co-adsorbed TiO_2 film in region from 300 nm to 750 nm, suppress charge recombination, prolong electron lifetime, and decrease the total resistance of DSSCs. The optimized cell device co-sensitized by BPPI/N719 dye gives a short circuit current density of 12.98 m A cm^（-2）, an open circuit voltage of 0.73 V,and a fill factor of 0.66 corresponding to an overall conversion efficiency of 6.22% under standard global AM 1.5 solar irradiation, which is much higher than that of device solely sensitized by N719（5.29%）under the same conditions. Mechanistic investigations are carried out by various spectral and electrochemical characterizations.
