Ultrasensitive V doped WO₃ 1D nanorods heterojunction photodetector with pronounced photosensing activities

In this study, vanadium-doped tungsten oxide (V-WO₃) nanorods heterostructures are designed by a simple, facile, and eco-friendly hydrothermal method and applied for photo-sensing activities. Physical characterization results indicate the phase purity, crystalline nature, tuneable energy bandgap, higher surface area, and successful formation of V doped WO₃ nanorods. Optoelectronic properties reveal pronounced photo-sensing capabilities of the designed material demonstrating efficient charge transfer. The photocurrent density is enhanced with laser power. Large values of open-circuit voltage (V_oc) and short-circuit current (I_sc) in the range of 0.91 V and 28 mA/cm², respectively, are obtained at 56 mW/cm² power. The I_sc is enhanced considerably as a function of power intensity of laser due to the formation of large number of photo-induced electron-hole pairs and large value of built-in potential. Furthermore, to estimate the response time of the device, the measured temporal photoresponse is 4500 A/W, several-fold higher than previously reported materials, associated with suppression in the dark current. In addition, the detectivity of V doped WO₃ NRs photodetector lies in the range of 5.15×10¹¹ Jones and the calculated value of detectivity and EQE is ~70%. These results are interesting and provide a roadmap to design ultrasensitive photodetectors.