Enhanced\nPhotodetection Performance of WSe<sub>2</sub>/V<sub>2</sub>O<sub>5</sub> Nanocomposite on Flexible Substrate:\nSynergistic Advantages and Improved Efficiency

The\ntwo-dimensional (2D) chalcogenide WSe<sub>2</sub>/V<sub>2</sub>O<sub>5</sub> composite nanostructures were synthesized using the\nhydrothermal method and extensively characterized with various spectroscopic\ntechniques. X-ray diffraction analysis confirmed the hexagonal crystal\nstructure exhibiting space symmetry of <i>P</i>6<sub>3</sub>/<i>mmc</i>. Scanning electron microscopy images provided\ninsights into the irregular and nonuniform morphology. Optical spectrum\nanalysis indicated a band gap value of 2.01 eV for 15% WSe<sub>2</sub>/V<sub>2</sub>O<sub>5</sub> nanostructures, as determined by the\nWood and Tauc equation. Photoluminescence (PL) excitation spectra\nat emission wavelengths of 550 and 750 nm exhibited broad emission\nattributed to self-trapped excitons for V<sub>2</sub>O<sub>5</sub> and WSe<sub>2</sub> nanostructures. Under excitation at λ<sub>exc</sub> = 365 nm, PL emission spectra displayed distinct peaks\nat 550 and 750 nm, demonstrating the ability to emit vivid red light.\nA device optimized for photoresponsivity (<i>R</i>) of approximately\n7.80 × 10<sup>–1</sup> A W<sup>–1</sup> and detectivity\n(<i>D</i>) of around 8.65 × 10<sup>11</sup> Jones,\nand quantum efficiency of approximately 3.42 × 10<sup>–2</sup> A W<sup>–1</sup> were achieved at a wavelength of 390 nm\nwhile using a lamination sheet as a substrate. These findings underscore\nthe capability of devices for efficient photoconversion at specified\nwavelengths, indicating potential applications in sensing, imaging,\nand optical communication. The photoresponsivity of the device remained\nstable at 3.38 × 10<sup>–3</sup> A W<sup>–1</sup> at 0° and 3.09 × 10<sup>–3</sup> A W<sup>–1</sup> at 55° bending angle. This indicates the resilience of device\nto mechanical strain, making it ideal for flexible and wearable sensor\napplications. The structural, morphological, and optical characterizations\nconfirm the suitability of luminescent WSe<sub>2</sub>/V<sub>2</sub>O<sub>5</sub> chalcogenide for practical optoelectronic applications,\nespecially in display technologies.