Enhancing the optoelectronic properties of V2O5 thin films through Tb doping for photodetector applications

Abstract

Using highly economical and scalable nebulizer-aided spray pyrolysis approach, a high-quality terbium (Tb) doped vanadium pentoxide (V2O5) thin film-based optical sensor was developed. To investigate the effects of various terbium doping concentrations on its growth and optoelectronic features, the structural properties as well as its elemental composition, surface morphology, photoluminescence, optical, and current-voltage (I-V) characteristics were examined. An orthorhombic structure with orientation along the (010) plane was found to be existing in the X-ray diffraction pattern of Tb-doped V2O5 thin films with increase in the crystallite size upto 3 % Tb-doped V2O5 films. The prevalence of dense nanorods is observed in all the films while analyzing their micrograph from a field emission scanning electron microscope. Also it is noted that the addition of 3 % Tb dopants increases UV absorption by lowering its energy gap from 2.43 to 2.37 eV. A strong green emission peak at 530 nm and weak UV bands were noted in the PL spectrum due to higher crystalline quality, free from defects and native flaws for the 3% Tb-doped V2O5. Terbium-doped V2O5 films exhibited elevated UV photo response and photoelectric properties than their pristine form. Among various doping concentrations, 3 % terbium in V2O5 thin film exhibited a maximum response (4.72 × 10−1 A/W), detectivity (7.82 × 1010 Jones), external quantum efficiency (110 %), and high photo-switching characteristics. This study confirms the optimal 3 % Tb dopant concentration plays a significant role in enhancing the UV–visible photo-sensing behavior of the V2O5 thin films. Data availability statementThe raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.