Analysis of structural and UV photodetecting properties of ZnO nanorod arrays grown on rotating substrate

• Published in: Journal of sol-gel science and technology 2018-02, Vol.85 (2), p.458-469
• Main Authors: Shakernejad, R., Khayatian, A., Ramazani, A., Akhtarianfar, S. F., Kashi, M. Almasi
• Format: Article
• Language: English
• Subjects: Ceramics; Chemistry and Materials Science; Coalescing; Composites; Electron microscopy; Field emission microscopy; Glass; Inorganic Chemistry; Materials Science; Nanorods; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper: Sol-gel and hybrid materials for optical; photonic and optoelectronic applications; Properties (attributes); Scanning electron microscopy; Substrates; X-ray diffraction; Zinc oxide
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-017-4540-7

ZnO nanorods (NRs) were successfully synthesized on seed layered substrate by a novel rotational hydrothermal method. The effect of substrate rotational speed on the growth of ZnO NRs were systematically characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). With an increase of the rotational speed, the mean diameter of the ZnO NRs decreased from ~ 43 nm in ZnO NRs grown on a steady substrate to ~27 nm in a sample with 60 rpm while the number density was increased about one order. The optical studies indicated that band gap of ZnO NRs was shifted towards higher values with increasing speed up to 60 rpm and then decreases gradually. The electrical resistance variation of samples was described according to structural properties of NRs and their coalescence, where the increasing of NRs lateral junction through substrate rotation, improves the electrons transition in samples. Finally, photosensing properties of ZnO based ultraviolet (UV) detectors were investigated. It was observed that the photdetector based on ZnO NRs grown at 120 rpm shows an optimum performance with sensitivity 570 and responsivity 1.9 A/W. Graphical abstract