DFT and TD-DFT calculations of HOMO and LUMO energies and photovoltaic properties are carried out on four selected pentathiophene donor and one IDIC-4F acceptor molecules using B3LYP and PBE0 functionals for the groun...DFT and TD-DFT calculations of HOMO and LUMO energies and photovoltaic properties are carried out on four selected pentathiophene donor and one IDIC-4F acceptor molecules using B3LYP and PBE0 functionals for the ground state energy calculations and CAM-B3LYP functional for the excited state calculations.The discrepancy between the calculated and experimental energies is reduced by correlating them with a linear fit.The fitted energies of HOMO and LUMO are used to calculate the Voc of an OSC based on these donors and acceptor blend and compared with experimental values.Using the Scharber model the calculated PCE of the donor-acceptor molecules agree with the experiment.It has been found that fluorine substitution can be used to improve charge transport by reducing the electron and hole reorganization energies of the molecules.It is also found that the introduction of fluorine onto the donor pentathiophene unit of the donor molecule results in a change of polarity of the distributed charges in the molecule due to the high electronegativity of the fluorine atom.The quantum chemical potential(μ),chemical hardness(η)and electronegativity(χ),and electrostatic potential maps(EPMs)are also calculated to identify different charge distribution regions in all five molecules.展开更多
A study was carried out to find the variation in wave characteristics along the eastern Arabian Sea and the influence of swells in the nearshore waves at 3 locations during summer monsoon in 2010. Percentage of swells...A study was carried out to find the variation in wave characteristics along the eastern Arabian Sea and the influence of swells in the nearshore waves at 3 locations during summer monsoon in 2010. Percentage of swells in the measured waves was 75% to 79% at the locations with higher percentage of swells in the northern portion of Arabian Sea com-pared to that at the southern side. The significant wave height up to 4.7 m and maximum wave height up to 7.4 m was observed. The wave height was increasing from south to north with the average significant wave height at the northern location 20% more than that at the southern location due to the increase in the swell height. Waves having spectral peak period less than 6 s were not present during the summer monsoon period. There was no change in the average value of wave statistical parameters for data collected at 1/2, 3, 6, 12 and 24 h interval.展开更多
文摘DFT and TD-DFT calculations of HOMO and LUMO energies and photovoltaic properties are carried out on four selected pentathiophene donor and one IDIC-4F acceptor molecules using B3LYP and PBE0 functionals for the ground state energy calculations and CAM-B3LYP functional for the excited state calculations.The discrepancy between the calculated and experimental energies is reduced by correlating them with a linear fit.The fitted energies of HOMO and LUMO are used to calculate the Voc of an OSC based on these donors and acceptor blend and compared with experimental values.Using the Scharber model the calculated PCE of the donor-acceptor molecules agree with the experiment.It has been found that fluorine substitution can be used to improve charge transport by reducing the electron and hole reorganization energies of the molecules.It is also found that the introduction of fluorine onto the donor pentathiophene unit of the donor molecule results in a change of polarity of the distributed charges in the molecule due to the high electronegativity of the fluorine atom.The quantum chemical potential(μ),chemical hardness(η)and electronegativity(χ),and electrostatic potential maps(EPMs)are also calculated to identify different charge distribution regions in all five molecules.
文摘A study was carried out to find the variation in wave characteristics along the eastern Arabian Sea and the influence of swells in the nearshore waves at 3 locations during summer monsoon in 2010. Percentage of swells in the measured waves was 75% to 79% at the locations with higher percentage of swells in the northern portion of Arabian Sea com-pared to that at the southern side. The significant wave height up to 4.7 m and maximum wave height up to 7.4 m was observed. The wave height was increasing from south to north with the average significant wave height at the northern location 20% more than that at the southern location due to the increase in the swell height. Waves having spectral peak period less than 6 s were not present during the summer monsoon period. There was no change in the average value of wave statistical parameters for data collected at 1/2, 3, 6, 12 and 24 h interval.
