Efficiency Enhancing In Textile Solar Cells Using Nano Fibers

DSCs (Dye sensitized solar cells) have been attracting considerable attention because of their high efficiency, simple fabrication process and low production cost. Costeffectiveness is an important parameter for producing DSCs as compared to the widely used conventional Si-solar cells [1]. Among some high efficiency DSSCs, the anode film is usually a double-layered complex composed of a nano-sized and submicron-sized TiO2 particles, namely, nanocrystalline emitransparent TiO2 layer and light scattering layer [2].Recently, one dimensional nanomaterials, such as nanorods, nanotubes and nanofibers, have been proposed to replace the nanoparticles used in DSSCs because of their ability to improve the electron transport leading to enhanced electroncollection efficiencies in DSSCs . Of particular interest are electrospun TiO2 nanofibers playingthe role as a photoanode material in DSSCs, which have been shown to improve the electron transport efficiency and to enhance the light harvesting efficiency by scattering morelight in the red part of the solar spectrum . However, due to the smaller surface-to-volume ratio of TiO2nanofibers compared to that of TiO2 nanoparticles, the photocurrent of devices based on TiO2 nanofibers is lower than that of DSSCs using TiO2 nanoparticles. One approach toimprove the photocurrent is to develop a thicker TiO2 nanofiber photoanode in order to increase the total surface area. However, the recombination probability of the electrons will increase sharply if the thickness is greater than the electron diffusion length in the photoanode [3].Electrospun nanofiber anodes can offer high specific surface areas (ranging from hundreds to thousands of square meters per gram) and bigger pore sizes than nanoparticle or film anodes. This is because the solid or semi-solid electrolytes are too viscous to sufficiently penetrate the TiO2 layer. Nanofiberanodes with large and controllable pore sizes may increase the penetration of viscous polymer gel electrolytes [4]. On the other hand, electrospinning as one of the most simple, versatile, and cost-effective approaches [2].