Open Access NANO EXPRESS

Synthesis and Photoluminescence Properties of Porous Silicon Nanowire Arrays

Linhan Lin1, Siping Guo1, Xianzhong Sun1, Jiayou Feng1* and Yan Wang2

Author Affiliations

1 Department of Materials Science and Engineering, Key Lab of Advanced Materials, Tsinghua University, 100084, Beijing, People’s Republic of China

2 Institute of Microelectronics of Tsinghua University, 100084, Beijing, People’s Republic of China

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Nanoscale Research Letters 2010, 5:1822-1828  doi:10.1007/s11671-010-9719-6

Published: 5 August 2010

Abstract

Herein, we prepare vertical and single crystalline porous silicon nanowires (SiNWs) via a two-step metal-assisted electroless etching method. The porosity of the nanowires is restricted by etchant concentration, etching time and doping lever of the silicon wafer. The diffusion of silver ions could lead to the nucleation of silver nanoparticles on the nanowires and open new etching ways. Like porous silicon (PS), these porous nanowires also show excellent photoluminescence (PL) properties. The PL intensity increases with porosity, with an enhancement of about 100 times observed in our condition experiments. A “red-shift” of the PL peak is also found. Further studies prove that the PL spectrum should be decomposed into two elementary PL bands. The peak at 850 nm is the emission of the localized excitation in the nanoporous structure, while the 750-nm peak should be attributed to the surface-oxidized nanostructure. It could be confirmed from the Fourier transform infrared spectroscopy analyses. These porous SiNW arrays may be useful as the nanoscale optoelectronic devices.

Keywords:
Porous silicon nanowires; Electroless etching; Silver catalyst; Photoluminescence; Porosity