Size-dependent structural, morphological, optical, and electrical studies of hydrothermally synthesized TiO2 nanocorals for DSSC application

• Published in: Journal of materials science. Materials in electronics 2023-11, Vol.34 (32), p.2137, Article 2137
• Main Authors: Naveenkumar, N., Abhishek, A., Sridevi, D. V., Balu, Murali, Neppolian, B., Ramesh, V.
• Format: Article
• Language: English
• Subjects: Absorption spectra; Characterization and Evaluation of Materials; Chemical compounds; Chemistry and Materials Science; Cut off wavelength; Dyes; Electrochemical impedance spectroscopy; Materials Science; Morphology; Optical and Electronic Materials; Reaction time; Spectrum analysis; Structural analysis; Surface chemistry; Surface properties; Titanium dioxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-023-11520-5

In this paper, we report the titanium dioxide (TiO 2 ) nanocorals made by a hydrothermal method with various reaction times (24 h, 48 h, and 72 h) at 160 °C. The structural analysis evidenced the existence of sharp intense peaks showing that the samples have a well-crystalline nature in prepared TiO 2 nanocorals, as confirmed by PXRD patterns. Moreover, the UV absorption spectrum has been used to analyse the optical absorption, cut-off wavelength (∼ 350 nm) and calculated the direct optical bandgap ( E g ), which has found to be 3.23, 3.31, and 3.42 eV by Tauc relation with the straight-line slop method ( αhγ ) 2 = 0. The FE-SEM images show the formation of TiO 2 film nanocoral with morphologies due to the effect of increasing the reaction times. Additionally, the EDS spectrum confirmed the presence of the chemical compounds. The surface characteristics of the samples have been investigated at atomic and molecular levels using AFM microscopic analyser. The conversion efficiency of (TiO 2 -N719 dye) DSSCs has increased by doping with varying reaction times from 4.51 to 5.85% because of increasing reaction time the surface morphology of the particle size decreases due to the effect of dye molecules absorbed and superior light scattering capability for boosting the light harvesting efficiency. The results of electrochemical impedance spectroscopy of DSSCs also presented.