Improvement of the performance and stability of the ZnO nanoparticulate film electrode by surface modification for dye-sensitized solar cells

Serious glomerations of the ZnO nanoparticles are discovered when the dye adsorption process is carried out for a period of time in the N719 dye solution. The destruction of the ZnO surface and the formation of Zn2+/dye aggregates are confirmed and characterized. The overall conversion efficiencies of the cells extremely decrease when the sensitization time is prolonged. In order to fabricate protection layers surround the nanoparticles, Al2O3 and SiO2 are coated on the surface of ZnO nanoparticulate film by spin-coating method. The result demonstrates that the surface modification with Al2O3 and SiO2 can improve the acid stability and performance of ZnO nanoparticulate film electrode. It will provide an efficient approach to enhance the comprehensive properties of the ZnO based DSCs for future applications.