A series of shape-persistent polyphenylene dendritic C_(60)derivatives as the electron transport materials were designed and synthesized via a catalyst-free Diels-Alder[4+2]cycloaddition reaction.These increasing hype...A series of shape-persistent polyphenylene dendritic C_(60)derivatives as the electron transport materials were designed and synthesized via a catalyst-free Diels-Alder[4+2]cycloaddition reaction.These increasing hyperbranched scaffolds could effectively enhance the solubility;notably,both first and second generation dendrimers,C_(60)-G1 and C_(60)-G2,demonstrated more than 5 times higher solubilities than pristine C_(60).Furthermore,both simulated and experimental data proved their promising solution-processabilities as electron-transporting layers(ETLs)for perovskite solar cells.As a result,the planar p-i-n structural perovskite solar cell could achieve a maximum power conversion efficiency of 14.7%with C_(60)-G2.展开更多
Defect-based engineering of carbon nanostructures is becoming an important and powerful method to modify the electron transport properties in graphene nanoribbon FETs. In this paper, the impact of the position and sym...Defect-based engineering of carbon nanostructures is becoming an important and powerful method to modify the electron transport properties in graphene nanoribbon FETs. In this paper, the impact of the position and symmetry of the ISTW defect on the performance of low dimensional 9AGNR double-gate graphene nanoribbon FET (DG-GNRFET) is investigated. Analyzing the transmission spectra, density of states and current-voltage characteristics shows that the defect effect on the electron transport is considerably varied depending on the positions and the orientations (the symmetric and asymmetric configuration) of the ISTW defect in the channel length. Based on the results, the asymmetric ISTW defect leads to a more controllability of the gate voltages over drain current, and drain current increases more than 5 times. The results have also con rmed the ISTW defect engineering potential on controlling the channel electrical current of DG-AGNR FET.展开更多
By using nonequilibrium Green＇s function method and first-principles calculations, the electronic transport properties of doped C60 molecular devices were investigated. It is revealed that the C60 molecular devices s...By using nonequilibrium Green＇s function method and first-principles calculations, the electronic transport properties of doped C60 molecular devices were investigated. It is revealed that the C60 molecular devices show the metal behavior due to the interaction between the C60 molecule and the metal electrode. The current-voltage curve displays a linear behavior at low bias, and the currents have the relation of MI〉M3〉M4〉M2 when the bias voltage is lower than 0.6 V. Electronic transport properties are affected greatly by the doped atoms. Negative differential resistance is found in a certain bias range for C60 and C58BN molecular devices, but cannot be observed in C59B and C59N molecular devices. These unconventional effects can be used to design novel nanoelectronic devices.展开更多
有机光伏器件(organic photovoltaics,OPVs)相比较于晶硅电池,具有彩色轻柔、半透明和低成本大面积制造等优点而被广泛关注。氧化锌(ZnO)由于在电子输运、环境友好和低温溶液加工等方面的优势而成为OPVs电子传输层(electron transport l...有机光伏器件(organic photovoltaics,OPVs)相比较于晶硅电池,具有彩色轻柔、半透明和低成本大面积制造等优点而被广泛关注。氧化锌(ZnO)由于在电子输运、环境友好和低温溶液加工等方面的优势而成为OPVs电子传输层(electron transport layer,ETL)的关键材料之一。但是,ZnO纳米颗粒通常有大量的表面缺陷而影响其载流子传输性,其电学性能有待进一步提升。因此,通过混合溶液法利用不同浓度硼酸与氧化锌溶液直接混合涂覆成膜,调节与优化两者混合比例,研究硼掺杂ZnO作为ETL(B-ZnO)对OPVs光电性能的影响。当掺杂比例为8%时,B-ZnO基OPVs在一个标准太阳光下的最高能量转换效率达到了8.76%,相比于ZnO基器件(8.10%)提升了8.2%。这归因于硼酸的掺杂使ZnO ETL获得了更好的表面形貌和更优的电学性质,减少了界面缺陷态密度和增加了器件的内建电势,从而进一步提高了OPVs性能。该研究为便捷的ZnO元素掺杂在高效OPVs中的应用提供了新的思路和方法。展开更多
基金Projects(2017YFE0131900,2017YFB0404500)supported by National Key Research and Development Program of ChinaProjects(91833306,91733302,62075094)supported by the National Natural Science Foundation of China+1 种基金Project(202003N4004)supported by the Ningbo Natural Science Foundation,ChinaProject(2020GXLH-Z-014)supported by the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University,China。
文摘A series of shape-persistent polyphenylene dendritic C_(60)derivatives as the electron transport materials were designed and synthesized via a catalyst-free Diels-Alder[4+2]cycloaddition reaction.These increasing hyperbranched scaffolds could effectively enhance the solubility;notably,both first and second generation dendrimers,C_(60)-G1 and C_(60)-G2,demonstrated more than 5 times higher solubilities than pristine C_(60).Furthermore,both simulated and experimental data proved their promising solution-processabilities as electron-transporting layers(ETLs)for perovskite solar cells.As a result,the planar p-i-n structural perovskite solar cell could achieve a maximum power conversion efficiency of 14.7%with C_(60)-G2.
文摘Defect-based engineering of carbon nanostructures is becoming an important and powerful method to modify the electron transport properties in graphene nanoribbon FETs. In this paper, the impact of the position and symmetry of the ISTW defect on the performance of low dimensional 9AGNR double-gate graphene nanoribbon FET (DG-GNRFET) is investigated. Analyzing the transmission spectra, density of states and current-voltage characteristics shows that the defect effect on the electron transport is considerably varied depending on the positions and the orientations (the symmetric and asymmetric configuration) of the ISTW defect in the channel length. Based on the results, the asymmetric ISTW defect leads to a more controllability of the gate voltages over drain current, and drain current increases more than 5 times. The results have also con rmed the ISTW defect engineering potential on controlling the channel electrical current of DG-AGNR FET.
基金Project(07JJ3102) supported by the Natural Science Foundation of Hunan Province, ChinaProject(1343-74236000006) supported by the Graduate Foundation of Hunan Province, ChinaProject(11MY20) supported by the Mittal Entrepreneurship Program of China
文摘By using nonequilibrium Green＇s function method and first-principles calculations, the electronic transport properties of doped C60 molecular devices were investigated. It is revealed that the C60 molecular devices show the metal behavior due to the interaction between the C60 molecule and the metal electrode. The current-voltage curve displays a linear behavior at low bias, and the currents have the relation of MI〉M3〉M4〉M2 when the bias voltage is lower than 0.6 V. Electronic transport properties are affected greatly by the doped atoms. Negative differential resistance is found in a certain bias range for C60 and C58BN molecular devices, but cannot be observed in C59B and C59N molecular devices. These unconventional effects can be used to design novel nanoelectronic devices.
文摘有机光伏器件(organic photovoltaics,OPVs)相比较于晶硅电池,具有彩色轻柔、半透明和低成本大面积制造等优点而被广泛关注。氧化锌(ZnO)由于在电子输运、环境友好和低温溶液加工等方面的优势而成为OPVs电子传输层(electron transport layer,ETL)的关键材料之一。但是,ZnO纳米颗粒通常有大量的表面缺陷而影响其载流子传输性,其电学性能有待进一步提升。因此,通过混合溶液法利用不同浓度硼酸与氧化锌溶液直接混合涂覆成膜,调节与优化两者混合比例,研究硼掺杂ZnO作为ETL(B-ZnO)对OPVs光电性能的影响。当掺杂比例为8%时,B-ZnO基OPVs在一个标准太阳光下的最高能量转换效率达到了8.76%,相比于ZnO基器件(8.10%)提升了8.2%。这归因于硼酸的掺杂使ZnO ETL获得了更好的表面形貌和更优的电学性质,减少了界面缺陷态密度和增加了器件的内建电势,从而进一步提高了OPVs性能。该研究为便捷的ZnO元素掺杂在高效OPVs中的应用提供了新的思路和方法。
