Undoped and Cu, Sn, and Ti doped ZnO nanorods were synthesized on FTO substrates by the hydrothermal method and systematically characterized. XRD analysis confirmed a hexagonal wurtzite structure with a strong (002) preferential orientation, indicating vertical alignment along the c-axis. While the diffraction peak position remained unchanged for undoped and Cu doped ZnO, a slight shift toward lower angles was observed for Sn and Ti doped samples, attributed to lattice expansion due to dopant incorporation. FESEM analysis revealed a systematic variation in nanorod dimensions, with both length and diameter increasing up to Sn doping and decreasing for Ti doped samples, indicating dopant-dependent growth kinetics. EDX confirmed the presence of Zn, O, and the respective dopants without secondary phases, while XPS verified successful dopant incorporation and surface chemical states. Optical studies showed a slight decrease in band gap for Cu doped ZnO and an increase for Sn and Ti doped nanorods. The PL emission exhibited a minor redshift in the 500–550 nm region, consistent with a reduction in oxygen vacancy related defect states from undoped to Ti doped samples. • We synthesize dun-doped, Cu, Sn, and Ti doped transition metal oxide (ZnO) nanorods on fluorine doped tin oxide (FTO) glass substrates using a low temperature hydrothermal method. • The crystallite size and morphology of the ZnO nanorods strongly depend on the dopant species and the ionic radius of the substitutional dopant, which govern crystal growth behaviour and crystallinity. • UV–Visible spectroscopy showed a slight reduction in the optical band gap for Cu doped ZnO nanorods compared to undoped ZnO, followed by an increase for Sn and Ti doped ZnO nanorods. • Electrical measurements demonstrated that Sn doped ZnO nanorods exhibit the highest electrical conductivity compared to undoped, Cu doped, and Ti doped ZnO nanorods.
Rao et al. (Wed,) studied this question.