Enhanced Visible-Light Photodetection Using Polypyrrole Nanotube/Tungsten Diselenide Nanosheet Nanocomposites

In this study, we report the synthesis of polypyrrole nanotubes (PNTs) and their nanocomposites with tungsten diselenide nanosheets (WSe 2 NSs) via an in situ chemical polymerization method. The structural and optical properties of the synthesized PNT and PNT/WSe 2 NS nanocomposites were investigated using the X-ray diffraction technique, Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and UV–Visible spectroscopy. The morphological characteristics were also examined through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the successful formation of nanotubular structures of polymer and uniform nanocomposite architectures. To evaluate their electrical and optoelectronic performance, pristine PNT and WSe 2 NSs, along with PNT/WSe 2 NS nanocomposites, were employed as active materials in photoconductive devices fabricated on etched indium tin oxide substrates via a solution-based deposition process. The fabricated devices were tested under visible light with varying power densities and wavelengths to assess their photosensitivity, responsivity, detectivity, and response dynamics. The PNT/WSe 2 NS nanocomposite exhibited significantly enhanced photodetection performance compared to pure PNT, demonstrating a high responsivity of 24.7 mA W –1 and a detectivity of 1.35 × 10 10 Jones. Additionally, the nanocomposite showed improved photocurrent generation and complete visible spectral sensitivity. The enhanced performance is attributed to the synergistic effect of WSe 2 NSs and PNT, which facilitates efficient charge carrier separation and transport within the nanocomposite matrix. These findings highlight the potential of PNT/WSe 2 nanocomposites as promising materials for next-generation visible-light photodetectors.