The Research Of Photo-induced Charge Transfer Between C₆₀ And CdSe/CdS/ZnS Quantum Dots In Their Surface And Interface

Cage structure of C60 has low reduction potential, three-dimensional conjugate π electronic structure,throughout the ultraviolet visible light area and a smaller restructuring energy in the process of the electronic transfer etc, it can form a conjugated system structure paired with the electron donor to show a good electron acceptor. One-dimensional C60 nanomaterials is constructed by C60 molecules through self-assembly to form one-dimensional carbon nanomaterials, It not only has the structural characteristics of C60 molecule, but has the linear characteristics of nanofibers, a new type of one-dimensional carbon nanomaterials has just developed in recent years. Quantum dots have unique physical properties, such as dependence on electronic structure, large size extinction coefficient and the multi-exciton generation etc, making it has strong superiority to become a as photon receiver. In this paper, a double layer structure of C60-QD composite film samples were prepared by thermal evaporation and spin-coating methods. The C60 nanorods and modification of quantum dots C60 nanorods modified by quantum dots were prepared by liquid-liquid interface precipitation(LLIP). These assembly were studied for their morphology and optoelectronic prorerties. This paper covers the following three aspects:1. The study of the performance of C60 powder and CdSe/CdS/Zn S quantum dot composite materials.A double layer structure donor-receptor sample was synthesized by thermal evaporating a layer of C60 thin film and then spin coating a layer of quantum dots. DFM results indicate the C60 film prepared by hermal evaporation has good uniformity and compactness. The film of quantum dots by continuous spin is also uniformly. A fluorescence quenching in a certain extent and a surface photovoltage enhancement for this double layer structure composite film samples were found by the fluorescence(PL), surface photovoltage spectrum and I-V characterization measurement compared to the single C60 film. I-V curves shows the current has 3 orders of magnitude improvement whether in the dark state or under the light condition.2. The preparation of one dimensional fullerene C60 nanorods and study of its photoelectric properties.The large length-diameter of ratio C60 nanorods is prepared by the liquid-liquid interface precipitation method(LLIP), the distribution of the sample was homogeneous and no winding each other. The SEM, TEM and XRD characterization results indicate that single crystal structure of C60 nanorods growth along [110] direction. The broad and intense absorption and large SPV signal in the visible range suggests enhanced photoelectronic properties in comparison to pristine C60, which represents a newer type of functional materials that can be used to design optoelectronic devices. The FET device was set up by assembling a single C60 nanorod onto Au electrode by dielectrophoresis and the symmetric SB between this C60 nanorod and Au electrode.3. The preparation of quantum dot modified C60 nanorods and analysis of their performance.The large length-diameter ratio of CdSe/CdS/ZnS quantum dots modified C60 nanorods were prepared by LLIP method and in-situ growing method. C60 nanorods modified by CdSe/CdS/ZnS quantum dots have the fcc structure.A lot of quantum dots clad on the C60 nanorod with weak van der Waals force. UV-Vis spectra and the SPV results indicate that strong fluorescence quenching phenomenon happened in quantum dots and C60 nanorods interface and has also a greatly enhanced SPV signal compared to pure C60. A single C60 nanorod modified by CdSe/CdS/ZnS quantum dots device is prepared by a electric field method. Its cycle response to the light, the response speed and stability in dark and light condition were investigated by I-V measurement, we found that C60 nanorod modified by CdSe/CdS/ZnS quantum dots has a light sensitivity and quicker response to recover signal.