Cu-excess CuxAlO2 ceramics with delafossite phases were synthesized using sol-gel. In the composition range of 1≤x〈1. 04,there are no detectable non-delafossite phases. Weak diffraction peaks of CuO are observed whe...Cu-excess CuxAlO2 ceramics with delafossite phases were synthesized using sol-gel. In the composition range of 1≤x〈1. 04,there are no detectable non-delafossite phases. Weak diffraction peaks of CuO are observed when x ≥1.04. The room temperature conductivity of the CU1.04AlO2 sample is improved by nearly an order of magnitude over that of the CuAlO2 sample. The major defect mechanism responsible for the conductivity enhancement is proposed to be substitution defects of CuAl （Cu^2 ＋ ions substitute Al^3 ＋ ions）. The composition formula unit for Cu-excess Cux AlO2 may be expressed as Cu（All yCuy）O2.展开更多
Using a first-principle method, the electronic structures and the impurity formation energy of ZnO, ZnO （N）, ZnO （N＋B）, and ZnO （2N＋B） have been calculated, based on which the feasibility to obtain p-type ZnO ...Using a first-principle method, the electronic structures and the impurity formation energy of ZnO, ZnO （N）, ZnO （N＋B）, and ZnO （2N＋B） have been calculated, based on which the feasibility to obtain p-type ZnO ＆ discussed. According to the results, when ZnO is single doped by N, the acceptor level is deep, and the formation energy is negative, so the ideal p-type ZnO can not be obtained by this way. On the contrary, when 2N＋B are codoped into ZnO, the acceptor level becomes much lower, and the formation energy is positive, so it is a better way to obtain p-type ZnO.展开更多
Transparent p-type conducting SnO2/Al/SnO2 multilayer films were fabricated on quartz substrates by radio frequency(RF) sputtering using SnO2 and Al targets. The deposited films were annealed at a fix temperature of 5...Transparent p-type conducting SnO2/Al/SnO2 multilayer films were fabricated on quartz substrates by radio frequency(RF) sputtering using SnO2 and Al targets. The deposited films were annealed at a fix temperature of 500 °C for different time durations(1-8 h). The effect of annealing time on the structural, morphological, optical and electrical performances of SnO2/Al/SnO2 multilayer films was studied. X-ray diffraction(XRD) results show that all the p-type conducting films possess polycrystalline SnO2 with tetragonal rutile structure. Hall-effect results indicate that 500 °C for 1 h is the optimum annealing condition for p-type SnO2/Al/SnO2 multilayer films, resulting in a hole concentration of 1.14×1018 cm-3 and a low resistivity of 1.38 ?·cm, respectively. The optical transmittance of the p-type SnO2/Al/SnO2 multilayer films is above 80% within annealing time range of 1-8 h, showing maximum for the films annealed for 1 h.展开更多
We present a system study on the electronic structure and optical property of boron doped semiconducting graphene nanoribbons using the density functional theory. Energy band structure, density of states, deformation ...We present a system study on the electronic structure and optical property of boron doped semiconducting graphene nanoribbons using the density functional theory. Energy band structure, density of states, deformation density, Mulliken popular and optical spectra are considered to show the special electronic structure of boron doped semiconducting graphene nanoribbons. The C-B bond form is discussed in detail. From our analysis it is concluded that the Fermi energy of boron doped semiconducting graphene nanoribbons gets lower than that of intrinsic semiconducting graphene nanoribbons. Our results also show that the boron doped semiconducting graphene nanoribbons behave as p-type semiconducting and that the absorption coefficient of boron doped armchair graphene nanoribbons is generally enhanced between 2.0 eV and 3.3 eV. Therefore, our results have a great significance in developing nano-material for fabricating the nano-photovoltaic devices.展开更多
文摘Cu-excess CuxAlO2 ceramics with delafossite phases were synthesized using sol-gel. In the composition range of 1≤x〈1. 04,there are no detectable non-delafossite phases. Weak diffraction peaks of CuO are observed when x ≥1.04. The room temperature conductivity of the CU1.04AlO2 sample is improved by nearly an order of magnitude over that of the CuAlO2 sample. The major defect mechanism responsible for the conductivity enhancement is proposed to be substitution defects of CuAl （Cu^2 ＋ ions substitute Al^3 ＋ ions）. The composition formula unit for Cu-excess Cux AlO2 may be expressed as Cu（All yCuy）O2.
基金Supported by the Foundation for the Excellent Youth Scholars of Anhui Education Office under Grant No.2009SQRZ097ZDthe Foundation of Anhui Province Education Bureau under Grant No.KJ2008B262 the Foundation of Anhui University of Architecture under Grant No.20070601
文摘Using a first-principle method, the electronic structures and the impurity formation energy of ZnO, ZnO （N）, ZnO （N＋B）, and ZnO （2N＋B） have been calculated, based on which the feasibility to obtain p-type ZnO ＆ discussed. According to the results, when ZnO is single doped by N, the acceptor level is deep, and the formation energy is negative, so the ideal p-type ZnO can not be obtained by this way. On the contrary, when 2N＋B are codoped into ZnO, the acceptor level becomes much lower, and the formation energy is positive, so it is a better way to obtain p-type ZnO.
基金Project(NIPA-2013-H0301-13-2009) supported by the MKE,Korea,under the ITRC support program supervised by the NIPAProject(2012HIB8A2026212) supported by the MEST and NRF through the Human Resource Training Project for Regional Innovation,Kored
文摘Transparent p-type conducting SnO2/Al/SnO2 multilayer films were fabricated on quartz substrates by radio frequency(RF) sputtering using SnO2 and Al targets. The deposited films were annealed at a fix temperature of 500 °C for different time durations(1-8 h). The effect of annealing time on the structural, morphological, optical and electrical performances of SnO2/Al/SnO2 multilayer films was studied. X-ray diffraction(XRD) results show that all the p-type conducting films possess polycrystalline SnO2 with tetragonal rutile structure. Hall-effect results indicate that 500 °C for 1 h is the optimum annealing condition for p-type SnO2/Al/SnO2 multilayer films, resulting in a hole concentration of 1.14×1018 cm-3 and a low resistivity of 1.38 ?·cm, respectively. The optical transmittance of the p-type SnO2/Al/SnO2 multilayer films is above 80% within annealing time range of 1-8 h, showing maximum for the films annealed for 1 h.
基金supported by the Natural Science Foundation of Fujian Province of China (Grant No. A0220001)Science Research Project of Leshan Vocational & Technical College (Grant No. KY2011001)the Key Research Project in Science and Technology of Leshan (Grant No. 2011GZD050)
文摘We present a system study on the electronic structure and optical property of boron doped semiconducting graphene nanoribbons using the density functional theory. Energy band structure, density of states, deformation density, Mulliken popular and optical spectra are considered to show the special electronic structure of boron doped semiconducting graphene nanoribbons. The C-B bond form is discussed in detail. From our analysis it is concluded that the Fermi energy of boron doped semiconducting graphene nanoribbons gets lower than that of intrinsic semiconducting graphene nanoribbons. Our results also show that the boron doped semiconducting graphene nanoribbons behave as p-type semiconducting and that the absorption coefficient of boron doped armchair graphene nanoribbons is generally enhanced between 2.0 eV and 3.3 eV. Therefore, our results have a great significance in developing nano-material for fabricating the nano-photovoltaic devices.
