Surface photovoltage spectroscopy equations for cathode materials with an AlxGa1-xAs buffer layer are determined in order to effectively measure the body parameters for transmission-mode （t-mode） photocathode materi...Surface photovoltage spectroscopy equations for cathode materials with an AlxGa1-xAs buffer layer are determined in order to effectively measure the body parameters for transmission-mode （t-mode） photocathode materials before Cs-O activation. Body parameters of cathode materials are well fitted through experiments and fitting calculations for the designed AlxGa1-xAs/GaAs structure material. This investigation examines photo-excited performance and measurements of body parameters for t-mode cathode materials of different doping structures. It also helps study various doping structures and optimize structure designs in the future.展开更多
In the present work, we prepared two kinds of quantum sized ZnO particles whose size were 3 nm(P1) and 5 nm(P2), respectively, and studied their surface properties with surface photovoltage spectroscopy(SPS) and elect...In the present work, we prepared two kinds of quantum sized ZnO particles whose size were 3 nm(P1) and 5 nm(P2), respectively, and studied their surface properties with surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS). The photovoltaic response of the two samples showed opposite dependence on external electric field. And when electric field was applied, the thresholds of photovoltaic response of the two samples were all red shifted. The results showed that the surface properties of P1 were different from those of P2, because of their different preparation process. We assigned that basic zinc acetate structure exist on the surface of P1 sample. While for P2 sample prepared by aging P1, that kind of surface structure disappeared, but the particles might be doped with lithium ions in the aging process.展开更多
Hybrid microballs with polystyrene cores coated by titania nanoparticles were prepared by miniemulsion polymerization. The crystallization morphology and photovoltage properties of the hybrid particles after calcinati...Hybrid microballs with polystyrene cores coated by titania nanoparticles were prepared by miniemulsion polymerization. The crystallization morphology and photovoltage properties of the hybrid particles after calcination were characterized by Scanning Electron Microscope(SEM), X-ray diffraction and surface photovoltage spectra(SPS). The crystal morphology has a critical effect on the threshold. It is found that the materials become prous, the thresholds of TiO 2 particles blue-shift with their particle sizes decreasing and crystal phase changing from anatase TiO 2 to rutile TiO 2. The SPS results showed that the peak height was three times the height of common TiO 2 nanoparticles.展开更多
The effect of built-in field on the surface photovoltage(SPV) response of ZnO nanoparticles was investigated by means of surface photovoltage spectroscopy(SPS). From the results of in situ SPS in atmosphere and in vac...The effect of built-in field on the surface photovoltage(SPV) response of ZnO nanoparticles was investigated by means of surface photovoltage spectroscopy(SPS). From the results of in situ SPS in atmosphere and in vacuum, we suggest that the built-in field should be a main condition for producing SPV response. By comparison of SPS with PL in vacuum as well as in atmosphere, we deduce that by changing the ambience of ZnO, its functional properties can be modulated.展开更多
基金supported by the General Administra-tion for Quality Supervision of China(No.2008QK328)the Zhejiang Provincial Natural Science Foundation of China(No.Y5090150)
文摘Surface photovoltage spectroscopy equations for cathode materials with an AlxGa1-xAs buffer layer are determined in order to effectively measure the body parameters for transmission-mode （t-mode） photocathode materials before Cs-O activation. Body parameters of cathode materials are well fitted through experiments and fitting calculations for the designed AlxGa1-xAs/GaAs structure material. This investigation examines photo-excited performance and measurements of body parameters for t-mode cathode materials of different doping structures. It also helps study various doping structures and optimize structure designs in the future.
文摘In the present work, we prepared two kinds of quantum sized ZnO particles whose size were 3 nm(P1) and 5 nm(P2), respectively, and studied their surface properties with surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS). The photovoltaic response of the two samples showed opposite dependence on external electric field. And when electric field was applied, the thresholds of photovoltaic response of the two samples were all red shifted. The results showed that the surface properties of P1 were different from those of P2, because of their different preparation process. We assigned that basic zinc acetate structure exist on the surface of P1 sample. While for P2 sample prepared by aging P1, that kind of surface structure disappeared, but the particles might be doped with lithium ions in the aging process.
文摘Hybrid microballs with polystyrene cores coated by titania nanoparticles were prepared by miniemulsion polymerization. The crystallization morphology and photovoltage properties of the hybrid particles after calcination were characterized by Scanning Electron Microscope(SEM), X-ray diffraction and surface photovoltage spectra(SPS). The crystal morphology has a critical effect on the threshold. It is found that the materials become prous, the thresholds of TiO 2 particles blue-shift with their particle sizes decreasing and crystal phase changing from anatase TiO 2 to rutile TiO 2. The SPS results showed that the peak height was three times the height of common TiO 2 nanoparticles.
文摘The effect of built-in field on the surface photovoltage(SPV) response of ZnO nanoparticles was investigated by means of surface photovoltage spectroscopy(SPS). From the results of in situ SPS in atmosphere and in vacuum, we suggest that the built-in field should be a main condition for producing SPV response. By comparison of SPS with PL in vacuum as well as in atmosphere, we deduce that by changing the ambience of ZnO, its functional properties can be modulated.
