The organic polymer solar cell is recognized as one of the most competitive technologies of the next generation. Au nanoparticles and ZnO nanorods were combined to improve the inverted-structure low-bandgap polymer solar cells and enhance the absorption and efficiency of the devices. However, the Au nanoparticles tend to aggregate in solution, thus reducing the localized surface plasmon resonance (LSPR) effect. The cluster effect on the spectral range of enhancement in the absorption is investigated and the absorption characteristics of the LSPR receive proper modification through our experiment. After reducing the number of Au nanoparticle clusters, the LSPR effect in the devices was clearly verified. The proper combination of the Au nanoparticles and ZnO nanorods leads to the power conversion efficiency of the PTB7 : PC71BM inverted organic solar cell reaching 8.04% after optimizing the process conditions.

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Vanadium dioxide (VO2) has been proposed as a phase-change material in tunable photonic and optoelectronic devices. In such devices, a thin layer of VO2 is typically deposited on metallic or insulating surfaces. In this Letter, we report the reflectance spectra of a subwavelength structure consisting of a thin layer of VO2 deposited on a gold film in the near-infrared spectral range, particularly near the wavelength of 1550 nm, which is significant for telecommunication applications. Our results indicate that in the insulating phase of VO2, the air/VO2/Au structure can be considered as a Gires–Tournois resonant cavity whose maximum absorption wavelength can be tuned by adjusting the thickness of the VO2 layer. In contrast, in the metallic phase of VO2, the reflectance of the structure increases by an amount of the order of a few tens of units. The proposed structure can prospectively lead to new design concepts in tunable photonic and optoelectronic devices.

For polymer solar cells, the efficiency loss is caused by considerable carrier recombination in active layer based on low carrier diffusion length or low carrier collection. Here, to increase the carrier collection, ZnO nanorods are inserted between thin ZnO seed layer and active layer. Consequently, the carrier transport is improved by using ZnO nanorods, and then the carrier collection rate and the efficiency are enhanced.978-1-4799-5622-7/$31.00 ©2014 IEEE