Impact of Cu doping on the structural, morphological and optical activity of V2O5 nanorods for photodiode fabrication and their characteristics

• Published in: RSC advances Vol. 9; no. 29; pp. 16541 - 16553
• Main Authors: Thangarasu, R, Babu, B, N Senthil Kumar, Mon-Shu Ho, Balasundaram, O N, Elangovan, T
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 28.05.2019; The Royal Society of Chemistry
• Subjects: Chemical precipitation; Chemical synthesis; Chemistry; Copper; Crystal defects; Crystallization; Differential thermal analysis; Doping; Junction diodes; Morphology; Nanorods; Optical activity; Optoelectronics; Organic chemistry; Photodiodes; Residual stress; Vanadium pentoxide; X ray photoelectron spectroscopy
• ISSN: 2046-2069
• DOI: 10.1039/c8ra07717g

In this paper, we report a wet chemical precipitation method used to synthesize pure and Cu-doped V2O5 nanorods with different doping concentrations (CuxV2O5 where x = 3, 5 or 7 at%), followed by annealing at 600 °C and characterizations using several techniques. Indeed, a growth mechanism explaining the morphological evolution under the experimental conditions is also proposed. The XRD patterns revealed that all of the studied samples consist of a single V2O5 phase and are well crystallized with a preferential orientation towards the (200) direction. The presence of intrinsic defects and internal stresses in the lattice structure of the CuxV2O5 samples has been substantiated by detailed analysis of the XRD. Apart from the doping level, there was an assessment of identical tiny peaks attributed to the formation of a secondary phase of CuO. SEM images confirmed the presence of agglomerated particles on the surface; the coverage increased with Cu doping level. XPS spectral analysis showed that Cu in the V5+ matrix exists mainly in the Cu2+ state on the surface. The appearance of satellite peaks in the Cu 2p spectra, however, provided definitive evidence for the presence of Cu2+ ions in these studied samples as well. Doping-induced PL quenching was observed due to the absorption of energy from defect emission in the V5+ lattice by Cu2+ ions. We have proposed a cost-effective, less complicated but effective way of synthesizing pure and doped samples in colloidal form, deposited by the nebulizer spray technique on p-Si to establish junction diodes with enhanced optoelectronic properties.