Deep-ultraviolet plasmon resonance of Ni nanoparticles embedded in BaTiO3 matrix

A tunable nanocomposite structure, consisting of Ni nanoparticles (NPs) with various morphologies and controllable BaTiO3 (BTO) films, was designed using a pulse laser deposition method. The morphological transformation of NPs and the crystal structure of BTO could be modulated by the Ni NP concentration. The experimental demonstration of absorption and photoluminescence enhancement using surface plasmon resonance (SPR) excitation in the deep-ultraviolet (DUV) region was investigated. The splitting of the Ni SPR peak was found in the DUV region, accompanied by decreased band gaps as the Ni NP concentration increased. By photoluminescence analysis, more Ni NPs embedding could provide more electron-hole recombination possibilities, enhancing the optical emission intensity and widening the emission range from red to ultraviolet luminescence. The DUV optical response of Ni NPs with various morphologies was further verified by finite-difference time-domain calculations. Compared with the reported metal NPs using the DUV SPR effect, the smaller Ni NPs provide a new non-noble metal NPs alternative with a high performance SPR excitation in the DUV region beyond the previous Al-based materials, giving new opportunities for manipulating high-energy photons. •Surface plasmon resonance of Ni NPs in deep-ultraviolet region was demonstrated.•SPR peaks could be tuned by the shape and spacing of Ni NPs.•Photoluminescence performance could be enhanced by Ni NPs embedding.•SPR peak splitting in the DUV region was verified by experiments and calculations.•We provide a new alternative to SPR excitation in the DUV region.