Ordered Arrays of Dual-Diameter Nanopillars for Maximized Optical Absorption

Overview

Title: 

Ordered Arrays of Dual-Diameter Nanopillars for Maximized Optical Absorption

Abstract: 

Optical properties of highly ordered Ge nanopillar arrays are tuned through shape and geometry control to achieve the Optimal absorption efficiency Increasing the Ge materials filling ratio is shown to increase the reflectance while simultaneously decreasing the transmittance. with the absorbance showing a strong diameter dependency To enhance the broad band optical absorption efficiency. a novel dual-diameter nanopillar structure is presented, with a small diameter tip for minimal reflectance and a large diameter base for maximal effective absorption coefficient The enabled single-crystalline absorber material with a thickness of only 2 mu m exhibits an impressive absorbance of similar to 99% over wavelengths, lambda = 300-900 nm These results enable a viable and convenient route toward shape-controlled nanopillar-based high-performance photonic devices

Authors: 

Zhiyong Fan, Rehan Kapadia, Paul W. Leu, Xiaobo Zhang, Yu-Lun Chueh, Kuniharu Takei, Kyoungsik Yu, Arash Jamshidi, Asghar A. Rathore, Daniel J. Ruebusch, Ming Wu, Ali Javey

DOI: 

Journal: 

Nano Letters

Year: 

2010

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