We report an organic/inorganic hybridized nanocomposite consisting of a bi-functional poly（N-vinyl）-3-[p-nitrophenylazo]carbazolyl serves as a polymeric charge-transporting and second-order nonliner optical matrix, ...We report an organic/inorganic hybridized nanocomposite consisting of a bi-functional poly（N-vinyl）-3-[p-nitrophenylazo]carbazolyl serves as a polymeric charge-transporting and second-order nonliner optical matrix, and CdS nanoparticles as photosensitizers to manifest photorefractive （PR） effect. The unpoled PVNPAK film exhibits a second harmonic generation （SHG） coefficient of 4.7 pm/V due to the possibility of self-alignment of the azo chromophore. Significant enhancement of photoconductivity is noticed with the increase of CdS nanoparticles concentration. The photorefractive property of the polymer nanocomposites were determined by two-beam coupling （TBC） experiment. The TBC gain and diffraction efficiency of 11.89 cm-1 and 3.2% were obtained for PVNPAK/CdS at zero electrical field.展开更多
One of the strategies to tune current-voltage behaviors in organic diodes is to combine field-induced charge transfer processes with schottky barrier.According to this principle,a rectifying diode with hysteresis effe...One of the strategies to tune current-voltage behaviors in organic diodes is to combine field-induced charge transfer processes with schottky barrier.According to this principle,a rectifying diode with hysteresis effect was fabricated utilizing a hybrid of electroactive polystyrene derivative covalently tethered with electron-donor carbazole moieties and electrostatic linked with electron-acceptor CdTe nanocrystals.Current-voltage characteristics show an electrical switching behavior with some hysteresis is only observed under a negative bias,with three orders of On/Off current ratio.The hybrid material based rectifier exhibits a rectification ratio of six and its maximum rectified output current is about 5 × 10-5 A.The asymmetric switching is interpreted as the result of both field induced charge transfer and schottky barrier,capable of reducing the misreading of cross-bar memory.Meanwhile,chemical doping of CdTe nanocrystals instead of physical blend favor their uniform dispersion in matrix and stable operation of device.展开更多
We apply the Heyd-Scuseria-Ernzerhof hybrid functional calculation to study the（2, 3） nanotube codoped with various compositions of nitrogen and boron atoms. We find that the bandgaps and other properties of doped n...We apply the Heyd-Scuseria-Ernzerhof hybrid functional calculation to study the（2, 3） nanotube codoped with various compositions of nitrogen and boron atoms. We find that the bandgaps and other properties of doped nanotubes oscillate with the doped compositions. Our study should shed light on the understanding of the properties of doped small nanotubes. This might have potential in designing new nano electronic-devices.展开更多
基金Funded by the National Natural Science Foundation of China (No.50802069)the Natural Science Foundation of Wuhan University of Tech-nology (471-38650378)
文摘We report an organic/inorganic hybridized nanocomposite consisting of a bi-functional poly（N-vinyl）-3-[p-nitrophenylazo]carbazolyl serves as a polymeric charge-transporting and second-order nonliner optical matrix, and CdS nanoparticles as photosensitizers to manifest photorefractive （PR） effect. The unpoled PVNPAK film exhibits a second harmonic generation （SHG） coefficient of 4.7 pm/V due to the possibility of self-alignment of the azo chromophore. Significant enhancement of photoconductivity is noticed with the increase of CdS nanoparticles concentration. The photorefractive property of the polymer nanocomposites were determined by two-beam coupling （TBC） experiment. The TBC gain and diffraction efficiency of 11.89 cm-1 and 3.2% were obtained for PVNPAK/CdS at zero electrical field.
基金supported by the National Basic Research Pro-gram of China (973 projeet) (2009CB930600)National Natural Science Foundation of China (Grants 90406021,20704023,60876010,60706017,and 20774043)+3 种基金the Key Project of Chinese Ministry of Education (No. 104246, 208050, 707032, NCET-07-0446)the NSF of Jiangsu Province (Grants BK2008053, 08KJB510013, SJ209003and TJ207035)Research Fund for Postgraduate Innovation Project of Jiangsu Province (No. CX08B_083Z)STITP (No. 2009120)
文摘One of the strategies to tune current-voltage behaviors in organic diodes is to combine field-induced charge transfer processes with schottky barrier.According to this principle,a rectifying diode with hysteresis effect was fabricated utilizing a hybrid of electroactive polystyrene derivative covalently tethered with electron-donor carbazole moieties and electrostatic linked with electron-acceptor CdTe nanocrystals.Current-voltage characteristics show an electrical switching behavior with some hysteresis is only observed under a negative bias,with three orders of On/Off current ratio.The hybrid material based rectifier exhibits a rectification ratio of six and its maximum rectified output current is about 5 × 10-5 A.The asymmetric switching is interpreted as the result of both field induced charge transfer and schottky barrier,capable of reducing the misreading of cross-bar memory.Meanwhile,chemical doping of CdTe nanocrystals instead of physical blend favor their uniform dispersion in matrix and stable operation of device.
文摘We apply the Heyd-Scuseria-Ernzerhof hybrid functional calculation to study the（2, 3） nanotube codoped with various compositions of nitrogen and boron atoms. We find that the bandgaps and other properties of doped nanotubes oscillate with the doped compositions. Our study should shed light on the understanding of the properties of doped small nanotubes. This might have potential in designing new nano electronic-devices.
