Preparation of ZnO Light Trapping Materials and their Performance in Solar Cells

The one-step low temperature aqueous solution method was used to prepare the ZnO nanorod array light trapping structure on the surface of untextured single crystal silicon solar cells, and the nanorods were regulated by adjusting the growth temperature. The morphologies of ZnO nanorod arrays were analyzed by scanning electron microscopy to investigate the effect of growth temperature on the array parameters. X-ray diffraction, fluorescence spectrophotometer and UV-Vis-NIR spectrophotometer were used to characterize the crystal structure and optical properties of ZnO nanorod arrays. The results show that the ZnO nanorod arrays prepared with the low temperature aqueous solution method have good crystal quality, high transmittance and low reflectance. Compared with the two samples (untextured bare silicon and silicon with only SiN_x antireflection layer), the surface reflectance of silicon with ZnO light trapping structure is greatly reduced. The short-circuit current density and conversion efficiency of the solar cell with this light trapping structure show 30.19% and 33.87% enhancements compared to that without any treatments. The light trapping structure has good antireflection properties and the light confinement effect is easy to be optimized by regulating its growth conditions.