ZnS and Zn(OH)_(2) capped ZnS semiconductor quantum dots(QDs)have been synthesized by the colloidal chemical method using inorganic reagents.Transmission electron microscopy and electron diffraction results showed tha...ZnS and Zn(OH)_(2) capped ZnS semiconductor quantum dots(QDs)have been synthesized by the colloidal chemical method using inorganic reagents.Transmission electron microscopy and electron diffraction results showed that the monodispersed ZnS QDs have 1 to 5 nm in diameter and the wurtzite structure.The polarities of the precursors and surfactant solvents have shown strong effects on the properties of the photoluminescence for ZnS QDs.For ZnS QDs capped with a wider band gap Zn(OH)_(2) shell,the surface trap states were passivated and hence the band-edge emissions have been enhanced.展开更多
In this study, Gum Arabic (GA)/Graphite (Gr) composite material was prepared using solid state reaction method. The FTIR peaks obtained were referred to the binding of Gr with the active groups in GA, such as NH2, COO...In this study, Gum Arabic (GA)/Graphite (Gr) composite material was prepared using solid state reaction method. The FTIR peaks obtained were referred to the binding of Gr with the active groups in GA, such as NH2, COOH, CHO, CNC (alkyl amine) and C=CH (aromatic monosubstitution). Atomic diffusivity of Gr in GA was calculated using simple model and was found to varied randomly. This randomness might be due to the attachment of Gr with different active groups of GA. The addition of Gr results in improvement of the conductivity of GA to a far extend as it reaches the semiconductor range. The random variation in conductivities of the samples can be attributed to the effect of high frequency range, where the effect of phonon-electron is dominant. The samples subjected to the impedance spectroscopy (IS) for second and third time were acquired different diffusivities as well as conductivities. Such variations might indicate that IS was a processing technique similar to thermal treatment since it boosted the Gr atomic diffusion.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.69890225.
文摘ZnS and Zn(OH)_(2) capped ZnS semiconductor quantum dots(QDs)have been synthesized by the colloidal chemical method using inorganic reagents.Transmission electron microscopy and electron diffraction results showed that the monodispersed ZnS QDs have 1 to 5 nm in diameter and the wurtzite structure.The polarities of the precursors and surfactant solvents have shown strong effects on the properties of the photoluminescence for ZnS QDs.For ZnS QDs capped with a wider band gap Zn(OH)_(2) shell,the surface trap states were passivated and hence the band-edge emissions have been enhanced.
文摘In this study, Gum Arabic (GA)/Graphite (Gr) composite material was prepared using solid state reaction method. The FTIR peaks obtained were referred to the binding of Gr with the active groups in GA, such as NH2, COOH, CHO, CNC (alkyl amine) and C=CH (aromatic monosubstitution). Atomic diffusivity of Gr in GA was calculated using simple model and was found to varied randomly. This randomness might be due to the attachment of Gr with different active groups of GA. The addition of Gr results in improvement of the conductivity of GA to a far extend as it reaches the semiconductor range. The random variation in conductivities of the samples can be attributed to the effect of high frequency range, where the effect of phonon-electron is dominant. The samples subjected to the impedance spectroscopy (IS) for second and third time were acquired different diffusivities as well as conductivities. Such variations might indicate that IS was a processing technique similar to thermal treatment since it boosted the Gr atomic diffusion.
