Band edge emission enhancement by quadrupole surface plasmon-exciton coupling using direct-contact Ag/ZnO nanospheres.
Band edge emission enhancement by quadrupole surface plasmon-exciton coupling using direct-contact Ag/ZnO nanospheres.
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DOI：
10.1039/c2nr32906a
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发表时间：
2013-01
期刊：
影响因子：
6.7
通讯作者：
Yashu Zang;Xu He;Jing Li;Jun Yin;Kongyi Li;Chuang Yue;Zhiming Wu;Suntao Wu;Junyong Kang
中科院分区：
文献类型：
--
作者：
Yashu Zang;Xu He;Jing Li;Jun Yin;Kongyi Li;Chuang Yue;Zhiming Wu;Suntao Wu;Junyong Kang
采用激光辐照的方法在氧化锌中空纳米球(HNS)支撑结构上大面积制备了周期性银纳米球(Nb)阵列。利用优化的激光功率和一定尺寸和间距的球形支撑结构，将溅射沉积的银纳米薄膜聚集成有序的、大面积的二维AgNb阵列。在这种AgNb/ZnO HNS杂化结构上实现了明显的带边发射增强，并通过进一步的实验和理论分析揭示了其机理。通过在每个氧化锌HNS的顶部成功地制备出银-Nb的直接接触结构，在紫外区的金属NBS上实现了高度局域的四极模表面等离子体共振(SPR)，通过与ZnO激子的强耦合，可以有效地提高ZnO的Be发射。与偶极模SPR相比，四极模SPR对金属纳米粒子的尺寸不敏感，并且在宽带隙材料的Be区有一个共振频率，因此可以在相关的光电子器件中得到潜在的应用。
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.