Comparative analysis of ZnO nanorods grown on different substrates: Structural, surface, optical and electrical properties

Abstract

Zinc oxide (ZnO) nanorods were synthesized on Silicon, glass, fluorine-doped tin oxide (FTO) glass, and Nitinol substrates using a hydrothermal method at 90 °C for 6 h. XRD analysis confirmed that all samples exhibited a strong (002) preferred orientation, indicating the formation of highly c-axis–aligned hexagonal wurtzite ZnO. Among the substrates, Nitinol exhibited the highest crystallinity and the largest crystallite size (43.57 nm), which is attributed to its lower lattice mismatch and reduced dislocation density. FESEM showed that ZnO nanorods on Nitinol possessed a higher aspect ratio and greater length and diameter compared to other substrates. XPS studies revealed fewer oxygen vacancies and hydroxyl groups in nanorods grown on Nitinol, resulting in reduced lattice strain and stronger Zn–O bonding, as evidenced by a shift of the O 1s peak toward higher binding energies. Hall effect showed that ZnO nanorods grown on FTO glass exhibited the highest electrical conductivity.