The effects of coumarin additive on the properties of ZnO nanostructures

► Significant changes/improvements were observed in morphology and crystal structure. ► Average diameters of the structures decreased with increasing coumarin content. ► Coumarin affected coverage density and uniformity of the shape of the structures. ► The best crystallization was obtained in the solution with 5% coumarin. ► The electrical resistivity values increased with increasing coumarin content.