Photovoltaic enhancement of nanostructured boron-doped rutile phase TiO2 nanorods via facile hydrothermal method

• Published in: Journal of materials science. Materials in electronics 2022-04, Vol.33 (12), p.9471-9482
• Main Authors: Mokhtar, S. M., Ahmad, M. K., Soon, C. F., Hamed, N. K. A., Shimomura, M.
• Format: Article
• Language: English
• Subjects: Absorption spectra; Boron; Characterization and Evaluation of Materials; Chemistry and Materials Science; Crystal structure; Crystallinity; Dopants; Doping; Electrochemical impedance spectroscopy; Electrolytic cells; Electron microscopy; Electron recombination; Electron transport; Fluorine; Materials Science; Microscopy; Morphology; Optical and Electronic Materials; Photoelectric effect; Photoelectric emission; Photoelectrons; Photometers; Photovoltaic cells; Raman spectroscopy; Rutile; Solar cells; Spectroscopic analysis; Spectrum analysis; Structural analysis; Substrates; X ray photoelectron spectroscopy
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-07440-x

Several doping processes are being investigated for the enhancement and efficient utilization of TiO 2 properties with increased focus on the crystallinity and mobility of TiO 2 nanorods. In this study, boron (B) was chosen as the dopant for its small orbital states of B 3+ when compared to Ti 4+ . The B-doped TiO 2 nanorods were fabricated on pre-cleaned fluorine-doped tin oxide substrate using hydrothermal method. The structural characterization was done by X-ray diffraction spectroscopy with diffraction angle fixed at 0.5° which was further confirmed by Raman spectroscopy. X-ray photoelectron spectroscopy was employed to analyse the elemental composition of the samples while the morphological characterization was achieved with the use of field-emission scanning electron microscopy and transmission electron microscopy. The absorption spectra were obtained using UV–Visible spectroscopy and the bandgap calculated from Tauc’s plot. The photocurrent properties were analysed by photoelectrochemical-based self-powered photodetector. No significant changes were observed in the morphology of the TiO 2 nanorods after doping. Both the crystallinity and mobility of TiO 2 nanorods from the B atom were increased. X-ray photoelectron and UV–Vis spectroscopy both confirmed that B dopant was present in interstitial and substitutional positions in the TiO 2 lattice even in low B dopant concentration. The photocurrent analysis indicates increased output current from 5.0 µA of pristine nanorods, to 16.5 µA of 1.00 wt% B-doped rutile TiO 2 nanorods, implying their enhanced electron transport. This was also proven by electrochemical impedance spectroscopy analysis where 1.00 wt% of B-doped TiO 2 showed the lowest electron recombination rate at electrolyte/working electrode interface. The results of this study can be used to improve the activities of solar cells, UV photodetector, or for photocatalytic applications.