Exploiting Thermoplasmonic Effects for Laser-Assisted Preparation of Au Nanoparticles/InZnO Thin Film with Visible Range Photodetection Properties

Here, a new method is proposed for preparing gold nanoparticles (Au NPs)/indium-zinc-oxide (IZO) nanocomposite thin films based on photothermal mechanisms with near-Infrared (NIR) laser annealing, which allows integrating the nanomaterial on fragile substrates such as thin glass, plastic sheets, or 3D printed pieces. The Au NPs are first prepared by NIR laser dewetting of a thin Au layer. Then, the Au NPs are used to locally cure the semiconductor material and provide suitable electronic properties owing to their efficient thermoplasmonic effects under the NIR laser annealing conditions. Finally, the electronic properties of the Au NPs/IZO thin films are characterized in the dark and under light excitation. Good photoresponsivity at 410 nm (UV, >10⁰ A W⁻¹) is demonstrated, but interestingly, the presence of Au NPs significantly improves the detection ability to a longer wavelength range, such as to 515 nm (green, ≈5 × 10⁻³ A W⁻¹), even extending to 630 nm (red, ≈5 × 10⁻⁴ A W⁻¹), and 780 nm (NIR, ≈10⁻⁴ A W⁻¹). In addition, with the critical evaluation of dynamic light detection and lifetime trace (>22 d), the laser-annealed Au NPs/IZO photodetectors demonstrate useful operating reliability and stability.