Porosity as one of the crucial factors to film morphology affects the overall electrical current-voltage characteristics of dye-sensitized solar cell （DSC）. We search for the short-circuit current density, the open-...Porosity as one of the crucial factors to film morphology affects the overall electrical current-voltage characteristics of dye-sensitized solar cell （DSC）. We search for the short-circuit current density, the open-circuit voltage and the maximum power output as the main functional parameters of DSC closely related to porosity under different film thickness. The theoretical analyses show some exciting results. As porosity changes from 0.41 to 0.75, the short-circuit current density shows the optimal value when the film thickness is 8-10 μm. The open-circuit voltage presents different variation tendencies for the film thicknesses within 1-8 μm and within 10-30 μm. The porosity is near 0.41 and the film thickness is about 10 μm, DSC will have the maximum power output. The theoretical studies also illustrate that given a good porosity distribution, DSC can obtain an excellent short-circuit current characteristic, which agrees well with the experimental results reported in previous literature.展开更多
Based on the optimization of dye-sensitized solar cell (DSC) photoelectrodes pretreated with different methods such as electrodeposition,spin-coating and TiCl_(4) pretreatment,theoretical calculations are carried out ...Based on the optimization of dye-sensitized solar cell (DSC) photoelectrodes pretreated with different methods such as electrodeposition,spin-coating and TiCl_(4) pretreatment,theoretical calculations are carried out to interpret the internal electric mechanism.The numerical values,including the series resistance R_(s) and the shunt resistance R_(sh) corresponding to the equivalent circuit model,are well evaluated and confirm that the DSC has good performance with a high R_(sh) and a low R_(s) due to good electrical contact and a low charge recombination after the different modifications.The Ⅰ-Ⅴ curves are fifted in the case without series resistance,and account for the role of R_(s) in the output characteristics.It is found that when R_(s) tends to the infinitesimal,the short-circuit current Isc,the open-circuit voltage V_(oc) and the fill factor can be improved by almost 0.8-1.4,2.9 and 2.1-6.8%,respectively.展开更多
The TiO2 nanoporous film photoelectrode, as a crucial component of dye-sensitized solar cells, has been investigated. The photovoltaic properties and the dark current were studied by two surface modification methods. ...The TiO2 nanoporous film photoelectrode, as a crucial component of dye-sensitized solar cells, has been investigated. The photovoltaic properties and the dark current were studied by two surface modification methods. One was to apply a compact layer between the conductive glass substrate and nanoporous TiO2 film. Another was to produce TiO2 nanoparticles among the microstructure by TICl4 treatment. A suitable concentration and number of times for TICl4 treatment were found in our experiment. The dark current is suppressed by surface modifications, leading to a significant improvement in the solar cells performance. An excessive concentration of TICl4 will produce more surface states and introduce a larger dark current reversely. The dye is also regarded as a source of charge recombination in dark to some extent, due to an amount of surface protonations introduced by the interracial link in the conductive glass substrate/dye interface and dye/TiO2 interface.展开更多
The influence of reactor pressure on GaN layers grown by hydride vapour phase epitaxy （HVPE） is investigated. By decreasing the reactor pressure from0. 7 to 0.5 mm, the GaN layer growth mode changes from the island-...The influence of reactor pressure on GaN layers grown by hydride vapour phase epitaxy （HVPE） is investigated. By decreasing the reactor pressure from0. 7 to 0.5 mm, the GaN layer growth mode changes from the island-like one to the step flow. The improvements in structural and optical properties and surface morphology of GaN layers are observed in the step flow growth mode. The results clearly indicate that the reactor pressure, similarly to the growth temperature, is One of the important parameters to influence the qualities of GaN epilayers grown by HVPE, due to the change of growth mode.展开更多
基金Supported by the National Bauic Research Program of China under Grant No 2006CB202600, Funds of Chinese Academy of Sciences for Key Topics in Innovation Engineering under Grant No KGCX2-YW-326, the National Natural Science Foundation of China under Grant No 20703046, and the National Science Foundation of Nantong University under Grant No 08Z067.
文摘Porosity as one of the crucial factors to film morphology affects the overall electrical current-voltage characteristics of dye-sensitized solar cell （DSC）. We search for the short-circuit current density, the open-circuit voltage and the maximum power output as the main functional parameters of DSC closely related to porosity under different film thickness. The theoretical analyses show some exciting results. As porosity changes from 0.41 to 0.75, the short-circuit current density shows the optimal value when the film thickness is 8-10 μm. The open-circuit voltage presents different variation tendencies for the film thicknesses within 1-8 μm and within 10-30 μm. The porosity is near 0.41 and the film thickness is about 10 μm, DSC will have the maximum power output. The theoretical studies also illustrate that given a good porosity distribution, DSC can obtain an excellent short-circuit current characteristic, which agrees well with the experimental results reported in previous literature.
基金Supported by the National Basic Research Program of China under Grant No 2011CBA00700the National Natural Science Foundation of China under Grant Nos 21173228 and 11104150+1 种基金the Foundation of Key Laboratory of Novel Thin Film Solar Cells,Chinese Academy of Sciences under Grant No KF201106the Major Program of Natural Science Basic Research of Institution of Higher Education of Jiangsu Province under Grant Nos 08KJA510002 and 10KJA140043.
文摘Based on the optimization of dye-sensitized solar cell (DSC) photoelectrodes pretreated with different methods such as electrodeposition,spin-coating and TiCl_(4) pretreatment,theoretical calculations are carried out to interpret the internal electric mechanism.The numerical values,including the series resistance R_(s) and the shunt resistance R_(sh) corresponding to the equivalent circuit model,are well evaluated and confirm that the DSC has good performance with a high R_(sh) and a low R_(s) due to good electrical contact and a low charge recombination after the different modifications.The Ⅰ-Ⅴ curves are fifted in the case without series resistance,and account for the role of R_(s) in the output characteristics.It is found that when R_(s) tends to the infinitesimal,the short-circuit current Isc,the open-circuit voltage V_(oc) and the fill factor can be improved by almost 0.8-1.4,2.9 and 2.1-6.8%,respectively.
基金supported by National Basic Research Program of China （No. 2006CB202600） the Natural Science Foundation of Nantong University （No. 06Z120）+1 种基金 the Fund for High Technology Research of Jiangsu Province （No. BG2005022） ＂The Six Top Talents Project＂ of Jiangsu
文摘The TiO2 nanoporous film photoelectrode, as a crucial component of dye-sensitized solar cells, has been investigated. The photovoltaic properties and the dark current were studied by two surface modification methods. One was to apply a compact layer between the conductive glass substrate and nanoporous TiO2 film. Another was to produce TiO2 nanoparticles among the microstructure by TICl4 treatment. A suitable concentration and number of times for TICl4 treatment were found in our experiment. The dark current is suppressed by surface modifications, leading to a significant improvement in the solar cells performance. An excessive concentration of TICl4 will produce more surface states and introduce a larger dark current reversely. The dye is also regarded as a source of charge recombination in dark to some extent, due to an amount of surface protonations introduced by the interracial link in the conductive glass substrate/dye interface and dye/TiO2 interface.
基金Supported the National Natural Science Foundation of China under Grant No 10574130 and the Natural Science Foundation of Jiangsu Province under No BK2004403.
文摘The influence of reactor pressure on GaN layers grown by hydride vapour phase epitaxy （HVPE） is investigated. By decreasing the reactor pressure from0. 7 to 0.5 mm, the GaN layer growth mode changes from the island-like one to the step flow. The improvements in structural and optical properties and surface morphology of GaN layers are observed in the step flow growth mode. The results clearly indicate that the reactor pressure, similarly to the growth temperature, is One of the important parameters to influence the qualities of GaN epilayers grown by HVPE, due to the change of growth mode.
