Two-step Laser Ablation in Liquid-assisted Magnetic Fields for Synthesis Au:Pb Core/Shell NPs in Developing High-Performance Silicon-based Heterojunction Photodetector

The appealing fundamental, optical, and electrical characteristics of the core–shell configuration make it a potential problem in optoelectronic devices. By altering the preparation conditions, core–shell photovoltaic devices with high performance can be produced. This study describes laser ablation in liquid at 1064 nm for the fabrication of Au:Pb NPs heterojunction photodetectors. It was investigated the properties of the Au:Pb NPs core/shell were affected by an external magnetic field with laser ablation, the addition of a magnetic field enhances the core–shell’s crystallinity. The optical energy gap for Au:Pb nanoparticles rises from 2.069 to 2.084 eV in the presence of magnetic field. Applied magnetic field during the laser ablation process, leading to an increase in the concentration and decrease in the size of nanoparticles, which led to the increase absorbance, and higher efficiency of removal was with the magnetic field strength 250 mT. The product’s morphology shows the formation of a core–shell, and when an external magnetic field is applied, particle agglomerations as well as aggregation are diminished. This work creates and characterizes the Au:Pb/porous silicon (PS) photodetector via photodetector properties that were greatly enhanced by the magnetic field. The responsivity (Rλ) of the photodetector increased from 0.210 to 0.365 A/W at λ = 450 nm by increasing the magnetic field. Nevertheless, the resultant’s Au:Pb/PS showed the optimal stability of the photocurrent, indicating that Au:Pb NPs deposition can improve the stability of PS opto-electrical characteristics. Finally, the results showed a powerful, noticeable improvement with the presence of the magnetic field.