Role of aqueous ammonia on the growth of ZnO nanostructures and its influence on solid-state dye sensitized solar cells

Synthesis of various ZnO nanostructures for different zinc to ammonia concentration ratios by a single-step aqueous chemical method at relatively low temperature is reported here. These nanostructures show preferential growth along (002) direction as observed in XRD. Morphological characterization by SEM, TEM, HRTEM, and SAED patterns reveal the formation of nanostructures of different shape, size, aspect ratio, and the crystal lattice orientations, which are mainly influenced by zinc to ammonia concentration. These materials when used as photo anodes in dye sensitized solar cells, the sample with the mixture of pyramidal, short nanorods, and spherical nanoparticle exhibits maximum conversion efficiency of 0.123 % due to better dye loading and direct conduction pathway for electron transport.