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Plasmonic nanoparticles (NPs) have attracted significant attention due to their unique optical properties and broad optoelectronic and photonic applications. We investigate modifications of emission in hybrid structures formed by 60 nm silver NPs and GaN planar nanowires (NWs). Bare GaN NWs exhibit photoluminescence (PL) spectra dominated by broad bands peaking at ∼3.44 eV and ∼3.33 eV, attributed to basal plane stacking faults. In hybrids, two new narrow PL lines appear at 3.36 and 3.31 eV, resulting in PL enhancement at these energies. While the 3.36 eV line in hybrid structures can be explained using the Fröhlich resonance approximation based on the electric dipole concept, the appearance of two features at 3.36 and 3.31 eV indicates the splitting of resonance lines. This phenomenon is explained in framework of theoretical model based on the interaction of the dipole with its charge image, taking into account the quadrupole moment of the silver sphere and the quadrupole field of the charge image. A good agreement is obtained between the calculated Fröhlich resonance frequencies and the experimental PL lines in hybrid structures.

Resistivity, ρ ( T ), and magnetoresistance (MR) are investigated in the Cu _2 Zn _1− _x Cd _x SnS _4 single crystals for compositions x ≡ Cd/(Zn + Cd) = 0.15–0.24, in the temperature range of T ∼ 50–300 K in pulsed magnetic fields of B up to 20 T. The Mott variable-range hopping (VRH) conductivity is established within wide temperature intervals lying inside Δ T _M ∼ 60–190 K for different x . The deviations from the VRH conduction, observable above and below Δ T _M , are connected to the nearest-neighbor hopping regime and to the activation on the mobility threshold of the acceptor band (AB) with width W ≈ 16–46 meV. The joint analysis of ρ ( T ) and positive MR permitted determination of other important electronic parameters. These include the localization radius, α ≈ 19–30 Å, the density of the localized states, g ( μ ) ≈ (1.6–21) × 10 ^17 meV ^−1 cm ^−3 at the Fermi level μ , and the acceptor concentration, N _A ∼ (6–8) × 10 ^19 cm ^−3 , for various x and in conditions of different vicinity of the investigated samples to the metal–insulator transition. In addition, details of the AB structure, including positions of μ and of the mobility threshold, E _c , are found depending on the alloy composition.