The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orb...The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orbitals,electron localization function(ELF)and partial density of states(PDOS).Birefringence is evaluated by means of a Born effective charge approach based on modern polarization theory.The origin of the different responses of birefringence and second-harmonic generation(SHG)is explored,as well as the effect of spin-orbit coupling(SOC)on the band structure and optical properties is explored.The study of this paper can help to deeply understand the lone pairs and their contribution to optical property.展开更多
Various bond modes of the M-C（C5 ring） exist in metallocene compounds of group 14 heavier elements,mostly due to an intricate interaction between the lone electron pairs at the M center and the 6 p-electrons of the ...Various bond modes of the M-C（C5 ring） exist in metallocene compounds of group 14 heavier elements,mostly due to an intricate interaction between the lone electron pairs at the M center and the 6 p-electrons of the C5 ring.The tin（Ⅱ） metallocene complexes LSn R（L = HC[CMe（N-2,6-iPr2C6H3）]2,R = cyclopentadienyl,C5H5（1）; indenyl,C9H7（2）; fluorenyl,C（13）H9（3）） stabilized by the β-diketiminato ligand were prepared and utilized in the study on their solid and solution state structures.X-ray single-crystal diffraction data revealed an η~1-mode of the Sn-C（C5 ring） bond in each 1~3.However,the room temperature ~1H NMR spectral studies disclosed such a fluxional bonding mode in solution.The 119 Sn NMR studies suggested a quadruple coordination nature of the Sn center in 1 while the triple coordination manner was for the Sn atom in both 2 and 3.Then the variable-temperature（25~–75 ℃） ~1H NMR spectral studies for each 1~3 were performed,which detected the relaxation state structures of 1~3 at lower temperature.All of these results indicate a stereochemical activity of the lone electron pairs at the tin（Ⅱ） atom that definitely has an electronic interaction with the 6 p-electrons of the C5 ring.The observed Sn-C（C5 ring） bond modes appear influenced by either the metallocene size or the compound state existed.展开更多
研究了引入有机小分子尿素(urea)作为阴极缓冲层的以P3HT∶PCBM为活性层的体异质结聚合物太阳能电池(BHJ-PSCs)。通过溶液旋涂法制备尿素层,并且以不同的旋涂速度得到不同厚度的尿素。在模拟的标准太阳光(100 m W/cm2)照射下,以3000 r/...研究了引入有机小分子尿素(urea)作为阴极缓冲层的以P3HT∶PCBM为活性层的体异质结聚合物太阳能电池(BHJ-PSCs)。通过溶液旋涂法制备尿素层,并且以不同的旋涂速度得到不同厚度的尿素。在模拟的标准太阳光(100 m W/cm2)照射下,以3000 r/min的转速旋涂尿素得到的器件取得了9.15 m A/cm2的短路电流密度,此时对应的能量转换效率较不加尿素层时的效率提高了20%,由2.8%增加到3.36%。原子力显微镜的测试表明,尿素层的引入改善了有机层和Al电极的接触。暗态J-V曲线的研究以及外量子效率的分析说明尿素层的引入抑制了载流子的复合,促进了载流子的传输与收集。尿素分子中氧原子上的孤对电子和Al发生强烈的化学反应,有效保护了活性层免受蒸镀的Al原子因注入带来的破坏,这种保护行为减少了载流子的复合,提高了器件的性能。展开更多
基金supported by the National Natural Science Foundation of the People's Republic of China“Mechanistic study of the influence of ns^(2) cation intrinsic properties and coordination environment on birefringence and frequency doubling effects”(12264047),“The study of the mechanism of the influence of lead-oxygen polyhedra and their coordination environments on the gain of the frequency doubling effect”(11864040)Tianshan Talent Project of Xinjiang Uygur Autonomous Region of China“Design,synthesis and photofunctional study of novel rare earth phosphate materials”(2022TSYCJU0004)。
文摘The stereochemically active lone pairs around post-transition metal atoms play an important role in determining distorted lattice structure and optical response.The lone pair electrons are characterized by crystal orbitals,electron localization function(ELF)and partial density of states(PDOS).Birefringence is evaluated by means of a Born effective charge approach based on modern polarization theory.The origin of the different responses of birefringence and second-harmonic generation(SHG)is explored,as well as the effect of spin-orbit coupling(SOC)on the band structure and optical properties is explored.The study of this paper can help to deeply understand the lone pairs and their contribution to optical property.
基金National Natural Science Foundation of China(51872219)Fundamental Research Funds for the Central Universities(WUT:2020IVA097)Funds for Postdoctoral Innovative Research Posts in Hubei Province(20201jb010)。
基金supported by the National Natural Science Foundation of China(21473142 and 21673191)the National Innovative Research Team of China(IRT_14R31 and J1310024)
文摘Various bond modes of the M-C（C5 ring） exist in metallocene compounds of group 14 heavier elements,mostly due to an intricate interaction between the lone electron pairs at the M center and the 6 p-electrons of the C5 ring.The tin（Ⅱ） metallocene complexes LSn R（L = HC[CMe（N-2,6-iPr2C6H3）]2,R = cyclopentadienyl,C5H5（1）; indenyl,C9H7（2）; fluorenyl,C（13）H9（3）） stabilized by the β-diketiminato ligand were prepared and utilized in the study on their solid and solution state structures.X-ray single-crystal diffraction data revealed an η~1-mode of the Sn-C（C5 ring） bond in each 1~3.However,the room temperature ~1H NMR spectral studies disclosed such a fluxional bonding mode in solution.The 119 Sn NMR studies suggested a quadruple coordination nature of the Sn center in 1 while the triple coordination manner was for the Sn atom in both 2 and 3.Then the variable-temperature（25~–75 ℃） ~1H NMR spectral studies for each 1~3 were performed,which detected the relaxation state structures of 1~3 at lower temperature.All of these results indicate a stereochemical activity of the lone electron pairs at the tin（Ⅱ） atom that definitely has an electronic interaction with the 6 p-electrons of the C5 ring.The observed Sn-C（C5 ring） bond modes appear influenced by either the metallocene size or the compound state existed.
文摘研究了引入有机小分子尿素(urea)作为阴极缓冲层的以P3HT∶PCBM为活性层的体异质结聚合物太阳能电池(BHJ-PSCs)。通过溶液旋涂法制备尿素层,并且以不同的旋涂速度得到不同厚度的尿素。在模拟的标准太阳光(100 m W/cm2)照射下,以3000 r/min的转速旋涂尿素得到的器件取得了9.15 m A/cm2的短路电流密度,此时对应的能量转换效率较不加尿素层时的效率提高了20%,由2.8%增加到3.36%。原子力显微镜的测试表明,尿素层的引入改善了有机层和Al电极的接触。暗态J-V曲线的研究以及外量子效率的分析说明尿素层的引入抑制了载流子的复合,促进了载流子的传输与收集。尿素分子中氧原子上的孤对电子和Al发生强烈的化学反应,有效保护了活性层免受蒸镀的Al原子因注入带来的破坏,这种保护行为减少了载流子的复合,提高了器件的性能。
基金Supported by Science and Technology Research Pro⁃ject of Henan Province(172102210391)the Higher Vocational School Program for Key Teachers from Department of education of Henan Prov⁃ince(2019GZGG042)the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China(2018D01C079).
