Research On Fabrication Of Large-Sized Dye-Sensitized Solar Cells

The lack of fossile energies makes R&D of solar resources more and more popular, especially when nanoscience and technology is developing rapidly. Combined its uninque properties with solar cell technology, the semiconductor nanomaterials have been wildly used in dye-sensitized solar cells (DSC) and have attracted worldwide interest. TiO2is relatively fully investigated in DSCs and TiO2-DSCs have been emplored from laboratory scale to indudtrial production. Besides, ZnO nanomaterials, with merits of high electron mobility, wide band gap and easy manipulation of morphology, have been considered as an ideal alternative to TiO2.However, the relatively low energy conversion efficiency limits the ZnO-based DSCs’development. Especially few reports are on assembling large-sized ZnO-DSCs. In this study, we focus on the fabrication of large-sized DSCs, and the details are as follows:1) ZnO nanoaggregates were used as photoelectrode material in large-sized DSCs by manually screen-printing4times with thickness of～22μm. The large-sized ZnO-DSC with an active area of18.24cm2attainded short-circuit current density of11.06mA·cm-2, open-circuit voltage of0.64V and efficiency of2.56%.2) A TiO2ultrathin layer was introduced in the ZnO aggregate film by dipping methord to form a core-shell structure, leading to enhancement of open-circuit voltage to0.68V and short-circuit current density to12.35mA-cm"2, respectively, which is mainly attributed to the suppressed charge recombination and improved charge collection. Consequently, the efficiency reached as high as3.19%.3) The surface of ZnO aggregates became roughter after adding acetic acid into the screen printing paste. Such a morphological change of the ZnO film gave rise to the increase of the overall surface area from26.9m2·g-1to30.8m2·g-1, leading to an increase of dye-loading amount from1.867×0-7mol·cm-2to2.832×10-7mol·cm-2. Therefore, the current density and efficiency further increased to11.78mA·cm-2and3.14%, respectively. 4) Both methords mentioned above were adapted to fabricate large-sized ZnO-DSCs with an active area of18.24cm2. According to the J-V test, the ZnO electrodes with both optimizations attaind short-circuit current density of11.95mA·cm-2, open-circuit voltage of0.69V, leading to an efficiency of3.47%.5) Large-sized TiO2-DSC is also fabricated by semi-automatic screen-printing machine with avtive area of10×10cm2. Surlyn hotmelt foil with100μm thickness was used as the primary sealing material. Hot-press process was undergone at about110℃for a certain time at a pressure of0.5MPa.The as-prepared device could well work after30days outdoor.