Optimizing reaction time in hydrothermal synthesis of nanocomposites V2O5/PANI for improved photodetector applications performance

This study assesses the photodetection efficacy of a nanocomposite heterojunction photodetector utilizing V₂O₅, PANI, and V₂O₅/PANI thin films. The nanocomposites were manufactured by a hydrothermal approach for 6 and 8 hours, then coated onto silicon (Si) substrates using a spray-coating technique. X-ray diffraction (XRD) examination verified the orthorhombic crystalline structure of V₂O₅ and the semi-crystalline characteristics of PANI. The nanocomposite synthesis led to noticeable alterations in both structures, with the reaction duration markedly affecting the crystallinity. Raman spectroscopy identified unique vibrational modes for each component, and the composite spectra exhibited distinctive changes indicative of robust molecular interactions. FESEM and AFM investigations revealed improved surface texture and suitable roughness in the sample synthesized at 6 hours and 180 °C, facilitating optimal morphology for effective photocarrier production and transport. Photoluminescence (PL) experiments verified that the active spectrum response of the nanocomposite photodetector ranges from 300 to 700 nm. The device constructed with a 6-hour response time demonstrated optimum performance, with a responsivity of 0.383 μA/W, a detectivity of 1.77×1020 Jones, and an external quantum efficiency of 153.2% at a 2 V bias and 10 mW/cm² light intensity. The reaction and recovery durations were 0.62 and 0.59 seconds, respectively. The results indicate the structural and functional dependability of the V₂O₅/PANI nanocomposite, presenting a viable avenue for constructing efficient optoelectronic devices.