Fabrication Of Si Nanowires And Their Application In Novel Solar Cells

The development of crystalline silicon solar cells is hampered by their high-cost, complex process, and lower theoretical efficiency. Silicon (Si) nanowires, one-dimensional materials, have more superior photovoltaic properties than bulk silicon. Meanwhile, the unique physical structure of Si nanowires makes it possible to become potenital material for build new radial-junction solar cells. The objects of our research focus on the fabrication of Silicon nanowires and their application in novel silicon nanowire solar cells, the main contents are as follows:Based on metal assisted etching principle, Si nanowires were prepared by one-step or two-step methods. The size and morphology of Si nanowires were controlled by changing the etching time, etching temperature, the metal catalyst and oxidant. Finally, we have prepared two kinds of special micro-structure:flexible Si nanowire arrays and Si nanorods/nanowires composite structure.Study on the properties of organic material polyethylene ethylenedioxythiophene thiophene:polystyrene sulfonate (PEDOT:PSS). The transmittance, work function, conductivity of PEDOT:PSS films were improved by doping nanomaterial and lithium bistrifluoromethane sulfonimide (LiTFSI). Finally, we fabricated the Si/PEDOT:PSS solar cell and studied on the influence of PEDOT:PSS films.Combining Si nanowires with PEDOT:PSS solution, we have constructed radial-junction solar cells. The performance of solar cells was optimized by turning the length of nanowires, the spin-coating speed of PEDOT:PSS solution and structure parameters of electrode. The short circuit current density and efficiency of solar cell were 34.67 mA/cm2 and 9.69% which has an obviously improvement.