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A unique vapour transport cum glancing angle deposition (VT-GLAD) technique was employed to fabricate titanium dioxide (TiO2) nanowires (NWs). The NWs were grown and assembled to form the clusters. Both brookite (412) and rutile (002) phase for TiO2 was obtained from X-ray diffraction (XRD). The d spacing of ~ 1.37 Å was calculated from the transmission electron microscopy (TEM) of TiO2 NWs, which corresponds to (002) crystal plane. The silver (Ag) nanoparticles (NPs) on TiO2 NWs were grown using thermal evaporation cum GLAD technique. The presence of Ag NPs on the TiO2 NWs enhanced the photoconduction as compared to bare TiO2 NWs device. The maximum photosensitivity of the Ag NPs/TiO2 NWs based device was recorded ~ 1.6 times compared to the bare TiO2 NWs based device at − 2.5 V. The Ag NPs containing device was highly UV sensitive and maximum responsivity for the device was calculated to be ~ 2.3 A/W at 370 nm. The device also possessed high responsivity rejection (RR) ratio of ~ 6.5 between UV (370 nm) and visible (450 nm) light. The Ag NPs decorated TiO2 NWs based detector also showed response to white light. The different concentration of glucose into deionised (DI) water-based solution was detected precisely under white light illumination. The normalised (light/dark) detector current/glucose concentration value was decreased from ~ 0.19 to ~ 0.05 at − 2.5 V, with an increase in glucose concentration into the solution from 40 mg/dl to 200 mg/dl. [ABSTRACT FROM AUTHOR]

Nanowires acts as a potential component in photodetectors (PDs) owing to its superior capacity to generate morphology-dependent broad absorption spectrum. In this study, we have demonstrated an efficient self-powered PD based on the radial heterostructure of the MgO capping layer on top of TiO 2 nanowires (RHNWs). RHNWs are highly sensitive under deep ultraviolet (UV) illumination when compared to TiO 2 -MgO axial heterostructure nanowires (AHNWs) PD. The finite-difference time-domain (FDTD) method is used to simulate electric field distribution, absorption spectra and generation rate profile of the structures. The RHNWs device possesses two times lower leakage current (∼ 1.78 × 10−9 A) than AHNWs (∼ 3.84 ×10−9 A) at – 1.5 V. Theoretical analysis shows a higher photoconductive gain for RHNWs (∼ 12) than the corresponding AHNWs device (∼ 9.9). Maximum photoresponsivity of ∼ 18 A/W has been observed for RHNWs with a sharp rise time ( T r) ∼ 0.12 s and fall time (T f) ∼ 0.13 s at 200 nm (– 9 V) and the device also behaves like a self-powered PD under white light illumination. [Display omitted] • Fabrication of TiO 2 -MgO axial and radial heterstructure NWs PDs using E-beam. • FDTD simulation shows higher absorption rate in deep UV due to MgO capping. • RHNWs PDs possesses two times lower leakage current than AHNWs PDs at −1.5 V. • RHNWs PDs exhibits excellent switching performance at 200 nm illumination. • RHNWs PDs behaves like self-powered PDs under white light illumination. [ABSTRACT FROM AUTHOR]

Co-doping of Mg into chemically stable TiO 2 thin film is attractive for deep UV detection. In this report, we have fabricated ∼110 nm undoped TiO 2 thin film and Mg doped TiO 2 thin film based photodetectors on p-type Silicone substrates. The Mg doped TiO 2 thin film shows good hydrophobicity. The undoped TiO 2 thin film shows low deep UV besides high responsivity in the visible region. The Mg:TiO 2 photodetector shows a maximum of four times superior light sensitivity as compared to undoped TiO 2 thin film at 200 nm illumination. The Mg:TiO 2 thin film shows the countable temporal response at 290 nm but the detector possesses low responsivity in the visible region. • Synthesis of Mg:TiO 2 TF using E-beam evaporation system. • The main bandgap of TiO 2 was enhanced to 4.15 eV after incorporation of Mg. • Mg:TiO 2 TF shows good hydrophobicity as compared to undoped TiO 2 TF. • The Mg:TiO 2 UVPD shows a maximum of four times sensitivity at 200 nm. • The Mg:TiO 2 TF device shows superior temporal response at 290 nm. [ABSTRACT FROM AUTHOR]