OICC Press Journal of Theoretical and Applied Physics 2251-7235 19 5 2025 09 30 Optimizing reaction time in hydrothermal synthesis of nanocomposites V2O5/PANI for improved photodetector applications performance 10.57647/j.jtap.2025.1905.43 EN Tayba Abd Allatife Ibrahim Department of Physics, College of Science, University of Anbar, Ramadi, Iraq https://orcid.org/0009-0009-5446-6280 Obaid Al-Qayssei Ibraheem J Ibraheem Department of Chemistry, College of Science, University of Anbar, Ramadi, Iraq Journal Article 2025 09 30 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.