A Comparison Study of Au@Nb2O5 Core–Shell Nanoparticle Using Two Different Laser Flounces

Niobium oxide (Nb₂O₅), a promising semiconductor, has attracted significant attention for its distinctive optical and electronic properties. This study reports the synthesis of Au@Nb₂O₅ core–shell nanostructures using pulsed laser ablation in liquid. The structural characterization confirms the formation of orthorhombic T-Nb₂O₅, as verified by XRD analysis. The optical band gap of the Au@Nb₂O₅ nanostructures is tunable, ranging from 2.27 to 2.18 eV. Morphological studies using FE-SEM and TEM reveal that laser fluence plays a critical role, with particle size and shell thickness increasing at higher laser energies. Photoluminescence measurements show a broad visible emission (455–480 nm), highlighting the potential for tuning optical properties through laser parameters. Furthermore, the design and analysis of an Au@Nb₂O₅/Si heterojunction photodetector are presented, showcasing its suitability for advanced optoelectronic applications.