Facile synthesis of 3-D nanostructured zinc oxide aerogel and its application as photoanode material for dye-sensitized solar cells

In this paper, we report the synthesis of 3-D nanostructured zinc oxide (ZnO) aerogel through epoxide gelation sol-gel method. The XRD pattern indicates ZnO crystallized in wurtzite structure. The network structure of ZnO aerogel formed by the combination of spherical aggregates and platelets were revealed by the field emission scanning electron microscopic analysis. The size of these aggregates is in the range of 20-50 nm. Transmission electron microscope images show the chainlike network structure of ZnO aerogel and hexagonal shape of the particles. A maximum power conversion efficiency of 0.11% was achieved with ZnO (25%) and TiO2 (75%) mixed aerogel as bottom layer and an overlayer of TiO2 in quasi-solid dye sensitized solar cells. To realize better performance using ZnO as photoanode the chemical stability of the ZnO nanostructures should be improved which avoids the dissolution and formation of Zn2+ complexes at the interface and facilitates the dye regeneration and electron injection processes.