Developing a high-performance UV photodetector by improving polyaniline polymer properties with multi-walled carbon nanotubes

In this article, a multi-walled carbon nanotube/polyaniline film was prepared using spin-coating approaches for UV polymer nanocomposite photodetector application. We present enhanced optical characteristics of polyaniline and polyaniline doping concentrations of multi-walled carbon nanotubes (MWCNTs) thin films prepared by the spin-coating technique on an indium tin oxide substrate. We have observed the structural characteristics of composite films that match MWCNTs and polymers. Scanning electron microscopy was used to examine the surface morphology of the deposited films, and the results show that the polymer in the composites has been uniformly coated on the MWCNTs, increasing the MWCNT content. The current–voltage (I–V) characteristics of the manufactured devices demonstrate a notable increase in current with the percentage content of the MWCNT weight. The optical characteristics of the prepared films were demonstrated by ultraviolet–visible (UV–vis) light spectroscopy analysis. In detail, optical band gaps between 2.38 and 2.42 eV were noticed by UV-vis invesitigation; however, the behavior of photoresponsivity in the obtained photodetectors. A particular detectivity of 5.5 µA mW⁻¹ and a photoresponsivity of 10 × 10¹⁵ Jones were achieved using 300–700 nm laser energy. In the meantime, it was discovered that the expected response/recovery time of the addressed laser energy was 0.32 s and 0.35 s, respectively. Sample 2 has a specific detectivity and photoresponsivity of 12 × 10¹⁵ Jones and 9.5 µA mW⁻¹ were achieved, with a recover/response time of approximately 0.35 s and 0.33 s, respectively.