The electronic structure and optical properties of pure, C-doped, C~ codoped and C-F-Be cluster- doped ZnO with a wurtzite structure were calculated by using the density functional theory with the plane-wave ultrasoft...The electronic structure and optical properties of pure, C-doped, C~ codoped and C-F-Be cluster- doped ZnO with a wurtzite structure were calculated by using the density functional theory with the plane-wave ultrasoft pseudopotentials method. The results indicate that p-type ZnO can be obtained by C incorporation, and the energy level of Co above the valence band maximum is 0.36 eV. The ionization energy of the complex Zn16O14CF and ZnlsBeO14CF can be reduced to 0.23 and 0.21 eV, individually. These results suggest that the defect complex of ZnlsBeO14CF is a better candidate for p-type ZnO. To make the optical properties clear, we investigated the imaginary part of the complex dielectric function ofundoped and C-F-Be doped ZnO. We found that there is strong absorption in the energy region lower than 2.7 eV for the C-F-Be doped system compared to pure ZnO.展开更多
Based on the density functional theory （DFT）, using first-principles plane-wave ultrasoft pseudopotential method, the models of the unit cell of pure ZnO and two highly In-doped supercells of Zn0.9375In0.0625O and Z...Based on the density functional theory （DFT）, using first-principles plane-wave ultrasoft pseudopotential method, the models of the unit cell of pure ZnO and two highly In-doped supercells of Zn0.9375In0.0625O and Zn0.875In0.125O are constructed, and the geometry optimizations of the three models are carried out. The total density of states （DOS） and the band structures （BS） are also calculated. The calculation results show that in the range of high doping concentration, when the doping concentration is hihger than a specific value, the conductivity decreases with the increase of the doping concentration of In in ZnO, which is in consistence with the change trend of the experimental results.展开更多
Polar surfaces are prevalent in metal oxides,the interactions between surface species with polar surfaces are different from those with non-polar surfaces,a thorough understanding of the interactions is key to regulat...Polar surfaces are prevalent in metal oxides,the interactions between surface species with polar surfaces are different from those with non-polar surfaces,a thorough understanding of the interactions is key to regulate the performance of heterogeneous catalysts.In this work,we delve into the interaction of Pt_(n)(n=1-4)with polar ZnO(0001)-Zn and ZnO(0001)-O,and the influence of the surface polarity on the electronic structures and reactivity of Pt_(n)by using density functional theory calculations.The results suggest distinct differences in electronic structures of two exposed terminations,leading to different interactions with Pt_(n).The interaction between Pt_(n)and two terminations not only stabilizes the surface and clusters through polar compensation,but also induces opposite charges on the cluster at two terminations.Remarkably,the Pearson correlation coefficient reveals the interdependency between the electronic states of Pt_(n)and its performance in terms of small molecule adsorption/activation.These observations demonstrate the crucial role of surface polarity in regulating the electronic states and catalytic performance of active sites,and offer a possible design principle for supported catalysts.展开更多
Using the first-principles approach based upon the density functional theory （DFT）, we have studied the electronic structure of wurtzite ZnO systems doped with C at different sites. When Zn is substituted by C, the ...Using the first-principles approach based upon the density functional theory （DFT）, we have studied the electronic structure of wurtzite ZnO systems doped with C at different sites. When Zn is substituted by C, the system turns from a direct band gap semiconductor into an indirect band gap semiconductor, and donor levels are formed. When O is substituted by C, acceptor levels are formed near the top of the valence band, and thus a p-type transformation of the system is achieved. When the two kinds of substitution coexist, the acceptor levels are compensated for all cases, which is unfavorable for the p-type transformation of the system.展开更多
文摘The electronic structure and optical properties of pure, C-doped, C~ codoped and C-F-Be cluster- doped ZnO with a wurtzite structure were calculated by using the density functional theory with the plane-wave ultrasoft pseudopotentials method. The results indicate that p-type ZnO can be obtained by C incorporation, and the energy level of Co above the valence band maximum is 0.36 eV. The ionization energy of the complex Zn16O14CF and ZnlsBeO14CF can be reduced to 0.23 and 0.21 eV, individually. These results suggest that the defect complex of ZnlsBeO14CF is a better candidate for p-type ZnO. To make the optical properties clear, we investigated the imaginary part of the complex dielectric function ofundoped and C-F-Be doped ZnO. We found that there is strong absorption in the energy region lower than 2.7 eV for the C-F-Be doped system compared to pure ZnO.
基金the National Natural Science Foundation of China(Grant Nos.51261017 and 21261013)the Ministry of Education"Spring Sunshine" Plan Funding,China+1 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region,China(Grant No.2011BS0104)the College Science Research Project of Inner Mongolia Autonomous Region,China(Grant Nos.NJZY12068 and NJZZ13099)
文摘Based on the density functional theory （DFT）, using first-principles plane-wave ultrasoft pseudopotential method, the models of the unit cell of pure ZnO and two highly In-doped supercells of Zn0.9375In0.0625O and Zn0.875In0.125O are constructed, and the geometry optimizations of the three models are carried out. The total density of states （DOS） and the band structures （BS） are also calculated. The calculation results show that in the range of high doping concentration, when the doping concentration is hihger than a specific value, the conductivity decreases with the increase of the doping concentration of In in ZnO, which is in consistence with the change trend of the experimental results.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.22303085,22102150 and 22172146)the Zhejiang Provincial Natural Science Foundation of China(LQ24B030014 andLQ21B030010).
文摘Polar surfaces are prevalent in metal oxides,the interactions between surface species with polar surfaces are different from those with non-polar surfaces,a thorough understanding of the interactions is key to regulate the performance of heterogeneous catalysts.In this work,we delve into the interaction of Pt_(n)(n=1-4)with polar ZnO(0001)-Zn and ZnO(0001)-O,and the influence of the surface polarity on the electronic structures and reactivity of Pt_(n)by using density functional theory calculations.The results suggest distinct differences in electronic structures of two exposed terminations,leading to different interactions with Pt_(n).The interaction between Pt_(n)and two terminations not only stabilizes the surface and clusters through polar compensation,but also induces opposite charges on the cluster at two terminations.Remarkably,the Pearson correlation coefficient reveals the interdependency between the electronic states of Pt_(n)and its performance in terms of small molecule adsorption/activation.These observations demonstrate the crucial role of surface polarity in regulating the electronic states and catalytic performance of active sites,and offer a possible design principle for supported catalysts.
基金supported by the National Natural Science Foundation of China(No.10775088)the Key Program of Theoretical Physics of Shandong Province
文摘Using the first-principles approach based upon the density functional theory （DFT）, we have studied the electronic structure of wurtzite ZnO systems doped with C at different sites. When Zn is substituted by C, the system turns from a direct band gap semiconductor into an indirect band gap semiconductor, and donor levels are formed. When O is substituted by C, acceptor levels are formed near the top of the valence band, and thus a p-type transformation of the system is achieved. When the two kinds of substitution coexist, the acceptor levels are compensated for all cases, which is unfavorable for the p-type transformation of the system.
