Band edge emission enhancement by quadrupole surface plasmon-exciton coupling using direct-contact Ag/ZnO nanospheres

Periodic Ag nanoball (NB) arrays on ZnO hollow nanosphere (HNS) supporting structures were fabricated in a large area by a laser irradiation method. The optimized laser power and spherical supporting structure of ZnO with a certain size and separation were employed to aggregate a sputtering-deposited Ag nano-film into an ordered, large-area, and two dimensional Ag NB array. A significant band edge (BE) emission enhancement of ZnO HNSs was achieved on this Ag NB/ZnO HNS hybrid structure and the mechanism was revealed by further experimental and theoretical analyses. With successfully fabricating the direct-contact structure of a Ag NB on the top of each ZnO HNS, the highly localized quadrupole mode surface plasmon resonance (SPR), realized on the metal NBs in the ultraviolet region, can effectively improve the BE emission of ZnO through strong coupling with the excitons of ZnO. Compared with the dipole mode SPR, the quadrupole mode SPR is insensitive to the metal nanoparticle's size and has a resonance frequency in the BE region of the wide band gap materials, hence, it can be potentially applied in related optoelectronic devices

The Design and Implementation of Geospatial Information Verification Middle Platform for Natural Resources Government Affairs

Geospatial Information Verification Mid-End Platform for Natural Resource Administration is designed in response to issues such as repeated development, low scalability, and inconsistent verification rules in existing approval and supervision application systems. We first discussed the architecture of the middle platform and micro-services and also examined the business requirements. Secondly, we presented the architecture of the spatial information verification platform. Finally, the application method in the construction land approval business is introduced. Practical applications proved that the spatial information verification platform is highly scalable and maintainable, with reusable business components and data services for a variety of government affairs application systems

In-plane Anisotropy of Quantum Transport in Artificial Two-dimensional Au Lattices

We report an experimental observation and direct control of quantum transport in artificial two-dimensional Au lattices. Combining the advanced techniques of low-temperature deposition and newly developed double-probe scanning tunneling spectroscopy, we display a two-dimensional carrier transport and demonstrate a strong in-plane transport modulation in the two-dimensional Au lattices. In well-ordered Au lattices, we observe the carrier transport behavior manifesting as a band-like feature with an energy gap. Furthermore, controlled structural modification performed by constructing coupled “stadiums” enables a transition of system dynamics in the lattices, which in turn establishes tunable resonant transport throughout a wide energy range. Our findings open the possibility of the construction and transport engineering of artificial lattices by the geometrical arrangement of scatterers and quantum chaotic dynamics

Evolution of wurtzite ZnO films on cubic MgO (001) substrates: A structural, optical, and electronic investigation of the misfit structures

We investigated the interface between hexagonal ZnO films and cubic MgO (001) substrates, fabricated via molecular beam epitaxy. X-ray diffraction and (scanning) transmission electron microscopy revealed that growth follows the single [0001] direction when the temperature of the substrate is above 200 °C, while when the substrate temperature is below 150 °C, growth initially is along [0001] and then mainly changes to [0-332] variants beyond a thickness of ～10 nm. Interestingly, a double-domain feature with a rotational angle of 30° appears during growth along [0001] regardless of the temperature, experimentally demonstrating the theoretical predictions for the occurrence of double rotational domains in such a heteroepitaxy [Grundmann et al., Phys. Rev. Lett. 105, 146102 (2010)]. We also found that the optical properties of the ZnO film are influenced greatly by the mutation of growth directions, stimulated by the bond-length modulations, as we determined from X-ray absorption spectra at Zn K edge. These results also showed the evolution of the 4pxy and 4pz states in the conduction band with the rise in the temperature for growth. We consider that our findings may well promote the applications of ZnO in advanced optoelectronics for which its integration with other materials of different phases is desirable. ? 2014 American Chemical Society