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The shell-like nano-structures (SLSs) own special ability to manipulate electromagnetic waves, and can be used as three-dimensional (3D) nano-antenna, highly efficient generator of second harmonic light, chiral metamaterials, and so on. However, to achieve this complicated geometry shape still remains challenging, which limits the related applications. In this paper, we propose a new method based on the microsphere self-assembly technology (MAT) to fabricate this type nano-structures, which is the use of basic SLSs (such as nano-cups or fragmented shells) as building blocks (BBs) to construct desired SLSs, just like that in architecture. Through establishing and using the related 3D geometric model, we design a great many of new SLSs, include some interesting structures, such as T-shape, 'maple leaf'-shape, and boat-shape structures. In theory, the number is infinite. In experiment, some new SLSs have been achieved, and their geometrical morphologies agree well with the designed. These new SLSs will provide a foundation for the related researches and applications.

To promote performance of organic photovoltaic device (OPV), a high-efficiency OPV structure is designed based on local surface plasmon (LSP) technology, which is composed of ITO/P3HT:PCBM/Ag nano-prisms array (ANPA)/Ag film/glass substrate. The ANPA used in this structure can effectively excite LSP and enhance the light absorption efficiency of OPV. The simulation results show that an up to 22-fold light absorption enhancement can be achieved through the parameter optimization of the ANPA. In this paper, we introduced a low-cost and easily-operated technology, poly-styrene spheres (PSs) self-assembly technology, to fabricate the ANPA, and then embedded them into the P3HT:PCBM blend layer. We measured the spectrum of this organic structure, and found a significant light absorption enhancement in the near-infrared waveband due to the excited LSP modes. The experimental results indicate this designed OPV structure together with the self-assembly technology is effective to enhance the light absorption efficiency of OPV, and has a very good application prospect.

We report a method of fabricating metal nano-grating by Solid immersion Interference lithography based on Backside exposure technique (SIB). Solid immersion lithography can improve the resolution of interference patterns by a factor of n (refractive index of prism), and backside exposure technique can improve the energy utilization ratio and protect the surface of the resist from being contaminated. In the process of fabrication, a high quality sacrificial layer (dielectric grating with high modulation depth and appropriate duty ratio) is important for transferring the patterns to the metal film. We optimized the exposure/development time by simulating the process of backside exposure. Simulation and experiment results show that: using 441.6nm wavelength laser, a series of subwavelength patterns (used as sacrificial layer) with high modulation depth and appropriate duty ratio can be gotten, the feature size of the patterns can be down to 80nm which is less than 0.18@l. Using optimized condition, high quality sacrificial layer can be achieved by using the backside exposure technique. Backside exposure technique has a greater exposure/development time tolerance for fabricating nano-patterns than the conventional interference lithography, which can be used for nano-metal grating fabrication.

We propose to use two-dimensional metal hole-array (TMH) and spatial light modulator (SLM) technology to construct a parallel direct-writing system. SLM and movable platform are used to control the system for realizing multi-beam parallel scanning exposure to fabricate arbitrary patterns. In this system TMH is the key component which focuses the incident light beams into light spots in the photoresist by exciting local surface plasmon polariton (LSPP). Parameters of TMH are optimized to improve the focusing efficiency and transmission depth of the light spots. Theoretical analysis and numerical simulations show that the feature size and transmission depth can reach sub-80nm and 90nm, respectively, by an optimized TMH, which is feasible for parallel direct writing lithography.