High‐Detectivity MOCVD‐Epitaxial h‐BN‐Based Vacuum UV Photodetectors With Pt Nanoparticle‐Engineered Localized Surface Plasmon Resonance Enhancement

This study addresses fabrication challenges in hexagonal boron nitride (h‐BN)‐based vacuum ultraviolet photodetectors (VUV PDs) by implementing platinum nanoparticle (Pt NP)‐induced localized surface plasmon resonance (LSPR) effects to enhance photoresponse characteristics. Size‐controlled Pt NPs (32 nm, 50 nm, 85 nm) are synthesized on metalorganic chemical vapor deposition (MOCVD)‐derived h‐BN surfaces through a cost‐effective dewetting process, with systematic evaluation under 185 nm VUV irradiation. The 32‐nm Pt NP‐enhanced device demonstrates optimal performance, achieving 1.02 mA/W responsivity (143% improvement) and 2.95 × 10 11 Jones specific detectivity (117% enhancement) at 20 V bias. Numerical simulations confirm that LSPR mechanisms intensify localized electric fields and photon absorption efficiency. This work presents the first LSPR‐enhanced h‐BN VUV photodetector utilizing Pt nanoparticles (NPs). The proposed design effectively addresses responsivity limitations in two‐dimensional material‐based detectors. Furthermore, it creates new opportunities for advancing extreme‐environment sensing and imaging technologies. The methodology maintains compatibility with scalable MOCVD fabrication processes, with performance improvements directly correlating to precise NP size optimization, suggesting plasmonic engineering as a critical pathway for next‐generation optoelectronic devices.