Ordered nanostructures have been extensively explored in nanophotonics and optoelectronics research, due to their intriguing properties of photon management. Specifically, the efficient light absorption property of three-dimensional semiconductor nanostructure arrays including nanowires/nanopillar, nanocones and nanowells have been widely applied in photovoltaics. Considering this, a systematic study of the optical nanopillar arrays is carried out in this work by finite-difference time-domain (FDTD) simulation, aiming to uncover the roles of different geometrical factors playing for photon management. Transverse resonance leaky modes are uncovered by analyzing the absorption contours with respect to nanopillar diameter and period. Based on this, a tower shaped nanopillar structu...[ Read more ]

Ordered nanostructures have been extensively explored in nanophotonics and optoelectronics research, due to their intriguing properties of photon management. Specifically, the efficient light absorption property of three-dimensional semiconductor nanostructure arrays including nanowires/nanopillar, nanocones and nanowells have been widely applied in photovoltaics. Considering this, a systematic study of the optical nanopillar arrays is carried out in this work by finite-difference time-domain (FDTD) simulation, aiming to uncover the roles of different geometrical factors playing for photon management. Transverse resonance leaky modes are uncovered by analyzing the absorption contours with respect to nanopillar diameter and period. Based on this, a tower shaped nanopillar structure is designed, which shows excellent performance for light absorption.

Apart from three-dimensional semiconductor nanostructures, metal nanostructures have recently attracted a lot of attention because of their plasmonic properties for potential applications such as surface enhanced Raman spectroscopy (SERS) and optical tweezers. In this work, a SERS system is designed, which is composed of gold nanostar arrays standing on metal substrate with a dielectric interlayer. The effect of different factors on the performance of this SERS system is investigated, by both FDTD simulation and Raman intensity measurement of experimental samples. With a rough surface, properly arranged gold nanostar arrays on Ag substrate with 1 nm dielectric interlayer can excite impressively strong Raman signals.

The results in this work not only greatly substantiate the understanding of the interplay between photons and nanostructures, but also serve as solid stepping stones toward the implementation of novel-structured optoelectronic devices, such as solar cells, photodetectors, light emitting devices and Raman sensors.