The structural, elastic, and electronic properties of NiAI alloyed with rare earth element （REE） Ce have been investigated by using density functional theory （DFT）. It is found that Ce has a strong AI site prefere...The structural, elastic, and electronic properties of NiAI alloyed with rare earth element （REE） Ce have been investigated by using density functional theory （DFT）. It is found that Ce has a strong AI site preference and causes lattice distortion of NiAI. The calculation of elastic constants shows that Ce increased both the hardness and the ductility of NiAI, which could be explained by the formation of new ionic bonds between AI （and Ni） and Ce and the enhancement of covalent bonds in NisAl7Ce. Our results are in good agreement with the available experimental data and other theoretical results.展开更多
The Autler-Townes （AT） splitting in femtosecond photoelectron spectrum of three-level Li2 molecules is theoretically investigated using time-dependent quantum wave packet method. With proper femtosecond laser pulses...The Autler-Townes （AT） splitting in femtosecond photoelectron spectrum of three-level Li2 molecules is theoretically investigated using time-dependent quantum wave packet method. With proper femtosecond laser pulses, three peaks of the AT splitting can be observed in the photoelectron spectrum. The AT splitting stems from rapid Rabi oscillation caused by intense ultrashort laser pluses. The effects of laser parameters on the molecular ionization dynamics are also discussed.展开更多
The potential energy function of nitrogen dioxide with the C2v symmetry in the ground state is represented using the simplified Sorbie-Murrell many-body expansion function in terms of the symmetry of NO2. Using the po...The potential energy function of nitrogen dioxide with the C2v symmetry in the ground state is represented using the simplified Sorbie-Murrell many-body expansion function in terms of the symmetry of NO2. Using the potential energy function, some potential energy surfaces of NO2（C2v, X^-^2A1）, such as the bond stretching contour plot for a fixed equilibrium geometry angle θ and contour for O moving around N-O （R1）, in which R1 is fixed at the equilibrium bond length, are depicted. The potential energy surfaces are analysed. Moreover, the equilibrium parameters for NO2 with the C2v, Cs and Dsn symmetries, such as equilibrium geometry structures and energies, are calculated by the ab initio （CBS-Q） method.展开更多
Effects of LO-phonon contribution on the electronic and the optical properties are investigated in a Cdo.sZno.2 Se/ZnSe quantum dot in the presence of magnetic field strength. The magneto-polaron induced hydro- genic ...Effects of LO-phonon contribution on the electronic and the optical properties are investigated in a Cdo.sZno.2 Se/ZnSe quantum dot in the presence of magnetic field strength. The magneto-polaron induced hydro- genic binding energy as a function of dot radius in the wide band gap quantum dot is calculated. The oscilla- tor strength and the spontaneous lifetime are studied taking into account the spatial confinement, magnetic field strength and the phonon contribution. Numerical calculations are carried out using variational formulism within the single band effective mass approximation. The optical properties are computed with the compact density matrix method. The magneto-polaron induced optical gain as a function of photon energy is observed. The results show that the optical telecommunication wavelength in the fiber optic communications can be achieved using CdSe/ZnSe semiconductors and it can be tuned with the proper applications of external perturbations.展开更多
ITIC is the milestone of non-fullerene small molecule acceptors used in organic solar cells. We study the electronic states and molecular orientation of ITIC film using photoelectron spectroscopy and x-ray absorption ...ITIC is the milestone of non-fullerene small molecule acceptors used in organic solar cells. We study the electronic states and molecular orientation of ITIC film using photoelectron spectroscopy and x-ray absorption spectroscopy. The negative integer charge transfer energy level is determined to be 4.00 ± 0.05 eV below the vacuum level, and the ionization potential is 5,75 ±0.10 eV. The molecules predominantly have the face-on orientation on inert substrates as long as the surfaces of the substrates are not too rough. These results provide the physical understanding of the high performance of ITIC-based solar ceils, which also afford implications to design more advanced photovoltaic small molecules.展开更多
基金supported by the National Natural Science Foundation of China under grant No.50871035
文摘The structural, elastic, and electronic properties of NiAI alloyed with rare earth element （REE） Ce have been investigated by using density functional theory （DFT）. It is found that Ce has a strong AI site preference and causes lattice distortion of NiAI. The calculation of elastic constants shows that Ce increased both the hardness and the ductility of NiAI, which could be explained by the formation of new ionic bonds between AI （and Ni） and Ce and the enhancement of covalent bonds in NisAl7Ce. Our results are in good agreement with the available experimental data and other theoretical results.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10374012 and 10674022.
文摘The Autler-Townes （AT） splitting in femtosecond photoelectron spectrum of three-level Li2 molecules is theoretically investigated using time-dependent quantum wave packet method. With proper femtosecond laser pulses, three peaks of the AT splitting can be observed in the photoelectron spectrum. The AT splitting stems from rapid Rabi oscillation caused by intense ultrashort laser pluses. The effects of laser parameters on the molecular ionization dynamics are also discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10376021 and 10676025, and the Scientific Research Fund of Sichuan Provincial Education Department （2006A131）.
文摘The potential energy function of nitrogen dioxide with the C2v symmetry in the ground state is represented using the simplified Sorbie-Murrell many-body expansion function in terms of the symmetry of NO2. Using the potential energy function, some potential energy surfaces of NO2（C2v, X^-^2A1）, such as the bond stretching contour plot for a fixed equilibrium geometry angle θ and contour for O moving around N-O （R1）, in which R1 is fixed at the equilibrium bond length, are depicted. The potential energy surfaces are analysed. Moreover, the equilibrium parameters for NO2 with the C2v, Cs and Dsn symmetries, such as equilibrium geometry structures and energies, are calculated by the ab initio （CBS-Q） method.
文摘Effects of LO-phonon contribution on the electronic and the optical properties are investigated in a Cdo.sZno.2 Se/ZnSe quantum dot in the presence of magnetic field strength. The magneto-polaron induced hydro- genic binding energy as a function of dot radius in the wide band gap quantum dot is calculated. The oscilla- tor strength and the spontaneous lifetime are studied taking into account the spatial confinement, magnetic field strength and the phonon contribution. Numerical calculations are carried out using variational formulism within the single band effective mass approximation. The optical properties are computed with the compact density matrix method. The magneto-polaron induced optical gain as a function of photon energy is observed. The results show that the optical telecommunication wavelength in the fiber optic communications can be achieved using CdSe/ZnSe semiconductors and it can be tuned with the proper applications of external perturbations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374258 and 11079028)
文摘ITIC is the milestone of non-fullerene small molecule acceptors used in organic solar cells. We study the electronic states and molecular orientation of ITIC film using photoelectron spectroscopy and x-ray absorption spectroscopy. The negative integer charge transfer energy level is determined to be 4.00 ± 0.05 eV below the vacuum level, and the ionization potential is 5,75 ±0.10 eV. The molecules predominantly have the face-on orientation on inert substrates as long as the surfaces of the substrates are not too rough. These results provide the physical understanding of the high performance of ITIC-based solar ceils, which also afford implications to design more advanced photovoltaic small molecules.
