Photovoltaic characteristics of dye-sensitized solar cells (DSSCs) using TiO2 nanotube (TNT) arrays as photoanodes were investigated. The TNT arrays were 3.3, 11.5, and 20.6 mu m long with the pore diameters of 50, 78...
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Photovoltaic characteristics of dye-sensitized solar cells (DSSCs) using TiO2 nanotube (TNT) arrays as photoanodes were investigated. The TNT arrays were 3.3, 11.5, and 20.6 mu m long with the pore diameters of 50, 78.6, and 98.7 nm, respectively. The longest TNT array of 20.6 mu m in length showed enhanced photovoltaic performances of 3.87% with significantly increased photocurrent density of 8.26 ***(-2). This improvement is attributed to the increased amount of the adsorbed dyes and the improved electron transport property with an increase in TNT length. The initial charge generation rate was improved from 4 x 10(21) s(-1).cm(-3) to 7 x 10(21) s(-1).cm(-3) in DSSCs based on optical modelling analysis. The modelling analysis of optical processes inside TNT-based DSSCs using generalized transfer matrix method (GTMM) revealed that the amount of dye and TNT lengths were critical factors influencing the performance of DSSCs, which is consistent with the experimental results.
We present a novel numerical approach to decrease the limits of the minimum paint thickness measurements of individual layers in multilayered structures using terahertz pulsed technique in reflection geometry. This me...
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ISBN:
(纸本)9781479982721
We present a novel numerical approach to decrease the limits of the minimum paint thickness measurements of individual layers in multilayered structures using terahertz pulsed technique in reflection geometry. This method combines the benefits of model-based material parameters extraction, a generalized transfer matrix method, and an evolutionary optimization algorithm. The proposed approach has been successfully applied to resolve individual layer thicknesses down to 5 mu m in multilayered automotive paint samples.
Photovoltaic current electric generation is directly related to the sunlight absorption in the active layers. The active layer material type and the optical losses remain the principal parameters, which have a greater...
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Photovoltaic current electric generation is directly related to the sunlight absorption in the active layers. The active layer material type and the optical losses remain the principal parameters, which have a greater effect on the amount of this absorption. This study focuses on improving the absorption in the silicon active layer of a silicon photovoltaic module by roughening the rear surface of the silicon layer. According to the generalized transfer matrix method, we derive the transmission from the incoherent multilayered module structure with a rough surface. We follow the optical model developed by Krauter and Hanitsch to derive the transmission into the silicon layer. Then the absorption is deduced from the difference between the transmission from the module and the transmission into the silicon. The effect of the incidence angles on the absorption is considered for different polarizations of light. The results of this study show a significant enhancement in the absorption in comparison to the absorption of the module with a polished rear surface. The short circuit current generated by the module with a rough rear surface silicon layer obtained is greater than that of the module with a polished rear surface.
In this paper, the optical parameters of an improved waveguide structure for a more efficient silicon solar cell are studied. Despite its favorable electronic, physical, and chemical properties, silicon remains a poor...
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In this paper, the optical parameters of an improved waveguide structure for a more efficient silicon solar cell are studied. Despite its favorable electronic, physical, and chemical properties, silicon remains a poor absorber of light. The optical losses due to the reflection at the air/glass interface of the cell and the transmission at its back are other factors, which limit the cell conversion efficiency. Consequently, several mechanisms for light trapping capable to increase the collection of the incident photons as electrical current and to decrease the transmission loss, have been developed. In this context, we propose a multilayer waveguide structure in which the sunlight is guided by a metamaterial layer and the transmission loss is eliminated by an aluminum back reflector. The reflection and transmission coefficients are derived by using the generalized transfer matrix method. The application of the law of conservation of energy allowed the determination of the absorption coefficient. These optical parameters are examined for several angles of incidence for s-polarized light, p-polarized light and unpolarized light. Simulation results show a significant reduction of reflection and a complete suppression of transmission.
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