Localized Surface Plasmon Resonance‐Enhanced Two‐Photon Excited Ultraviolet Emission of Au‐Decorated ZnO Nanorod Arrays

Abstract

ZnO nanorod arrays and their Au‐decorated counterparts are fabricated. The two‐photon excited ultraviolet emissions of these two samples are studied by selecting different excitation wavelengths according to the localized surface plamsmon resonance (LSPR) position of Au nanoparticles (NPs). It is found that the two‐photon excitation threshold of Au‐decorated ZnO sample is much lower than that of the as‐grown sample under an excitation corresponding to the LSPR absorption of Au NPs, such as 520 nm. Under the same excitation power, the UV emission intensity is strongly enhanced after the Au NPs are assembled on the surfaces of ZnO nanorods. This improvement is attributed to a strong local field enhancement generated by the LSPR of Au NPs. Experiments demonstrate that the resonant process depends on the excitation wavelength near or far from the LSPR peak of Au NPs. These studies provide direct evidence for the mechanism of LSPR‐enhanced UV emission of ZnO, and are helpful to design proper metal–semiconductor nanostructures with high luminescence efficiency.

Extinction of the zero-phonon line and the first-order phonon sideband in excitonic luminescence of ZnO at room temperature: the self-absorption effect

“…their ZPL lines) are almost fully eliminated for T >70 K, the FX-1LO peak then fully removed at T = 250 K, and the spectrum eventually completely dominated by the FX-2LO emission at 300 K. This temperature evolution tendency is well consistent with those reported by Iwai and Namba [13], as well as Klingshirn [15]. In fact, all reported room-temperature TPA-PL spectra of various ZnO always peak at $390 nm [7,15,[21][22][23][24]. Even for all laser spectra of various forms of ZnO at room temperature, their spectral centers always located at $390 nm [1][2][3][4][5][6][8][9][10][11][12][13][14][15][16][17][22][23][24][25].…”

Underlying mechanism of blue emission enhancement in Au decorated p-GaN film

“…[3][4][5][6][7][8] Among them, Au NPs were good candidates for enhancing photoluminescence (PL) of wide gap semiconductors with defect emission. [9][10][11] Traditionally, reports about this are focused on Au/ZnO composites. For example, Li et al observed 18-fold UV emission enhancement in Au coated ZnO lm.…”

Reagent concentration dependent variations in the stability and photoluminescence of silica-coated ZnO nanorods

“…[1][2][3][4][5] A variety of post-treatments, e.g. annealing, 6,7 plasma processing, 8,9 or coating with metal nanoparticles 10,11 or oxides, 12,13 have been explored with this aim in mind. The results and conclusions from different groups are frequently in disagreement, however, even in studies involving similar posttreatments.…”