Enhanced Photodetection Performance of WSe₂/V₂O₅ Nanocomposite on Flexible Substrate: Synergistic Advantages and Improved Efficiency

Abstract

The two-dimensional (2D) chalcogenide WSe 2 /V 2 O 5 composite nanostructures were synthesized using the hydrothermal method and extensively characterized with various spectroscopic techniques. X-ray diffraction analysis confirmed the hexagonal crystal structure exhibiting space symmetry of P 6 3 / mmc . Scanning electron microscopy images provided insights into the irregular and nonuniform morphology. Optical spectrum analysis indicated a band gap value of 2.01 eV for 15% WSe 2 /V 2 O 5 nanostructures, as determined by the Wood and Tauc equation. Photoluminescence (PL) excitation spectra at emission wavelengths of 550 and 750 nm exhibited broad emission attributed to self-trapped excitons for V 2 O 5 and WSe 2 nanostructures. Under excitation at λ exc = 365 nm, PL emission spectra displayed distinct peaks at 550 and 750 nm, demonstrating the ability to emit vivid red light. A device optimized for photoresponsivity ( R ) of approximately 7.80 × 10 –1 A W –1 and detectivity ( D ) of around 8.65 × 10 11 Jones, and quantum efficiency of approximately 3.42 × 10 –2 A W –1 were achieved at a wavelength of 390 nm while using a lamination sheet as a substrate. These findings underscore the capability of devices for efficient photoconversion at specified wavelengths, indicating potential applications in sensing, imaging, and optical communication. The photoresponsivity of the device remained stable at 3.38 × 10 –3 A W –1 at 0° and 3.09 × 10 –3 A W –1 at 55° bending angle. This indicates the resilience of device to mechanical strain, making it ideal for flexible and wearable sensor applications. The structural, morphological, and optical characterizations confirm the suitability of luminescent WSe 2 /V 2 O 5 chalcogenide for practical optoelectronic applications, especially in display technologies.

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