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
The ZnO quantum dot particles with an average particle size 3 nm and the ZnO nanorods with an average length of 80 nm and width about 14 nm were synthesized by the sol-gel method. The surface photovoltaic properties o...The ZnO quantum dot particles with an average particle size 3 nm and the ZnO nanorods with an average length of 80 nm and width about 14 nm were synthesized by the sol-gel method. The surface photovoltaic properties of ZnO nanoparticles were investigated by means of FISPS technique and the bands in FISPS were identified. The results show that the surface photovoltaic properties of ZnO nanoparticles make a great difference for the structures or sizes due to the quantum confinement effect. The photovoltaic response intensity of ZnO nanorods is two-orders of magnitude stronger than that of quantum dot particles. And it is found that the ZnO quantum dot particles exhibit significant quantum confinement properties of photogenerated charges. The photovoltaic response bands of ZnO nanorods are related to band-band transition and bound exciton transition, respectively.展开更多
The surface photovoltaic properties of four azo pigments(A, B, C, D) were studied by surface photovoltage spectra (SPS) and field induced surface photovoltage spectra (FISPS). The SPV responses of samples A and D were...The surface photovoltaic properties of four azo pigments(A, B, C, D) were studied by surface photovoltage spectra (SPS) and field induced surface photovoltage spectra (FISPS). The SPV responses of samples A and D were all enhanced when a negative electric field was applied and were all weaken when a positive voltage was applied. It shows that samples A and D indicate n type characteristics. On the contrary, samples B and C indicate p type characteristics. Combining with phase technique and molecular structure of azo pigments, the effect of group on Fermi energy level and conduction type of azo pigments was discussed.展开更多
The photovoltaic properties of dimeric porphyrin have been studied by means of surface photovoltage spectrum(SPS) and field induced surface photovoltage spectrum(FISPS). The results show that a negative SPV response b...The photovoltaic properties of dimeric porphyrin have been studied by means of surface photovoltage spectrum(SPS) and field induced surface photovoltage spectrum(FISPS). The results show that a negative SPV response band(P) appears in the long wave region which takes on n type character and the π π * transition band takes on p type character. P band disappears under high vacuum and appears under O 2 atmosphere. The photo charge transfer process generated between π π * transition band of dimeric porphyrin and P band, which has been attributed to the photo adsorption and photo desorption of O 2 on the surface of dimeric porphyrin.展开更多
本文采用水热法制备了γ-Bi_2Sn_2O_7并研究了其在可见光区的光电响应。Bi_2Sn_2O_7的晶体结构和光电响应特性分别用X射线衍射和表面光电压谱进行表征。研究结果表明,合成的Bi_2Sn_2O_7呈现γ相立方结构,通过吸收光谱估算光学带隙为2.67...本文采用水热法制备了γ-Bi_2Sn_2O_7并研究了其在可见光区的光电响应。Bi_2Sn_2O_7的晶体结构和光电响应特性分别用X射线衍射和表面光电压谱进行表征。研究结果表明,合成的Bi_2Sn_2O_7呈现γ相立方结构,通过吸收光谱估算光学带隙为2.67 e V,比α-Bi_2O_3(2.85 e V)的光学带隙小。Bi_2Sn_2O_7的光电响应相对于α-Bi_2O_3在可见光区展现出一定的优势,同时对外加电压有很强的响应。展开更多
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.
文摘The ZnO quantum dot particles with an average particle size 3 nm and the ZnO nanorods with an average length of 80 nm and width about 14 nm were synthesized by the sol-gel method. The surface photovoltaic properties of ZnO nanoparticles were investigated by means of FISPS technique and the bands in FISPS were identified. The results show that the surface photovoltaic properties of ZnO nanoparticles make a great difference for the structures or sizes due to the quantum confinement effect. The photovoltaic response intensity of ZnO nanorods is two-orders of magnitude stronger than that of quantum dot particles. And it is found that the ZnO quantum dot particles exhibit significant quantum confinement properties of photogenerated charges. The photovoltaic response bands of ZnO nanorods are related to band-band transition and bound exciton transition, respectively.
文摘The surface photovoltaic properties of four azo pigments(A, B, C, D) were studied by surface photovoltage spectra (SPS) and field induced surface photovoltage spectra (FISPS). The SPV responses of samples A and D were all enhanced when a negative electric field was applied and were all weaken when a positive voltage was applied. It shows that samples A and D indicate n type characteristics. On the contrary, samples B and C indicate p type characteristics. Combining with phase technique and molecular structure of azo pigments, the effect of group on Fermi energy level and conduction type of azo pigments was discussed.
文摘The photovoltaic properties of dimeric porphyrin have been studied by means of surface photovoltage spectrum(SPS) and field induced surface photovoltage spectrum(FISPS). The results show that a negative SPV response band(P) appears in the long wave region which takes on n type character and the π π * transition band takes on p type character. P band disappears under high vacuum and appears under O 2 atmosphere. The photo charge transfer process generated between π π * transition band of dimeric porphyrin and P band, which has been attributed to the photo adsorption and photo desorption of O 2 on the surface of dimeric porphyrin.
文摘本文采用水热法制备了γ-Bi_2Sn_2O_7并研究了其在可见光区的光电响应。Bi_2Sn_2O_7的晶体结构和光电响应特性分别用X射线衍射和表面光电压谱进行表征。研究结果表明,合成的Bi_2Sn_2O_7呈现γ相立方结构,通过吸收光谱估算光学带隙为2.67 e V,比α-Bi_2O_3(2.85 e V)的光学带隙小。Bi_2Sn_2O_7的光电响应相对于α-Bi_2O_3在可见光区展现出一定的优势,同时对外加电压有很强的响应。
