Developing controllable anisotropic wet etching to achieve silicon nanorods, nanopencils and nanocones for efficient photon trapping

Controllable hierarchy of highly regular, single-crystalline nanorod, nanopencil and nanocone arrays with tunable geometry and etch anisotropy has been achieved over large areas (>1.5 cm × 1.5 cm) by using an [AgNO3 + HF + HNO3/H2O2] etching system. The etching mechanism has been elucidated to originate from the site-selective deposition of Ag nanoclusters. Different etch anisotropies and aspect ratios can be accomplished by modulating the relative concentration in the [AgNO3 + HF + HNO3/H2O2] etching system. Minimized optical reflectance is also demonstrated with the fabricated nano-arrays. Overall, this work highlights the technological potency of utilizing a simple wet-chemistry-only fabrication scheme, instead of reactive dry etching, to attain three-dimensional Si nanostructures with different geometrical morphologies for applications requiring large-scale, low-cost and efficient photon trapping (e.g. photovoltaics).

[1]  Soojin Park,et al.  Fabrication of highly ordered silicon pin-in-a-hole nanostructures via chemical etching of nanopatterned polymer masks , 2011 .

[2]  François Léonard,et al.  Large area, dense silicon nanowire array chemical sensors , 2006 .

[3]  A. Javey,et al.  Shape-controlled synthesis of single-crystalline nanopillar arrays by template-assisted vapor-liquid-solid process. , 2010, Journal of the American Chemical Society.

[4]  Shufeng Bai,et al.  Wafer-scale patterning of sub-40 nm diameter and high aspect ratio (>50:1) silicon pillar arrays by nanoimprint and etching , 2008, Nanotechnology.

[5]  Deyu Li,et al.  Fabrication of silica nanotube arrays from vertical silicon nanowire templates. , 2003, Journal of the American Chemical Society.

[6]  Yi Cui,et al.  Broadband light management using low-Q whispering gallery modes in spherical nanoshells , 2012, Nature Communications.

[7]  Zongfu Yu,et al.  Optical absorption enhancement in amorphous silicon nanowire and nanocone arrays. , 2009, Nano letters.

[8]  Zhang,et al.  Atomistic Processes in the Early Stages of Thin-Film Growth , 1997, Science.

[9]  Ning-Bew Wong,et al.  Ordered silicon nanowire arrays via nanosphere lithography and metal-induced etching , 2007 .

[10]  M. D. De Volder,et al.  Engineering Hierarchical Nanostructures by Elastocapillary Self-assembly Angewandte Reviews , 2022 .

[11]  Zongfu Yu,et al.  Hybrid silicon nanocone-polymer solar cells. , 2012, Nano letters.

[12]  Xiao Hui Yang,et al.  Preparation technique for copper-plating on Si nanoporous pillar array , 2010 .

[13]  Peidong Yang,et al.  Silicon Vertically Integrated Nanowire Field Effect Transistors , 2006 .

[14]  Zhiyong Fan,et al.  Efficient photon capturing with ordered three-dimensional nanowell arrays. , 2012, Nano letters.

[15]  R. Howe,et al.  A review of the chemical reaction mechanism and kinetics for hydrofluoric acid etching of silicon dioxide for surface micromachining applications , 1993 .

[16]  Kui‐Qing Peng,et al.  Motility of Metal Nanoparticles in Silicon and Induced Anisotropic Silicon Etching , 2008 .

[17]  F. Wittea,et al.  In vivo corrosion of four magnesium alloys and the associated bone response , 2004 .

[18]  Enhanced Raman scattering from nanoparticle-decorated nanocone substrates: a practical approach to harness in-plane excitation. , 2010, ACS nano.

[19]  B. Schwartz,et al.  Chemical Etching of Silicon III . A Temperature Study in the Acid System , 1961 .

[20]  K L Klein,et al.  Formation of ultrasharp vertically aligned Cu-Si nanocones by a DC plasma process. , 2006, The journal of physical chemistry. B.

[21]  Bernd Rech,et al.  Nanowire arrays in multicrystalline silicon thin films on glass: a promising material for research and applications in nanotechnology. , 2012, Nano letters.

[22]  R. Voorhoeve,et al.  Selective Deposition of Silver on Silicon by Reaction with Silver Fluoride Vapor , 1972 .

[23]  C. Pan,et al.  Improved broadband and quasi-omnidirectional anti-reflection properties with biomimetic silicon nanostructures. , 2007, Nature nanotechnology.

[24]  Xiao Hui Yang,et al.  Effect of annealing temperature on the copper nanoparticles deposited on the silicon nanoporous pillar array , 2013 .

[25]  Andrew G. Glen,et al.  APPL , 2001 .

[26]  D. M. Knotter,et al.  Etching Mechanism of Vitreous Silicon Dioxide in HF-Based Solutions , 2000 .

[27]  Charles B. Musgrave,et al.  The mechanism of HF/H2O chemical etching of SiO2 , 2002 .

[28]  Yi Cui,et al.  Wafer-scale silicon nanopillars and nanocones by Langmuir-Blodgett assembly and etching , 2008 .

[29]  Zhiyong Fan,et al.  Strong light absorption of self-organized 3-D nanospike arrays for photovoltaic applications. , 2011, ACS nano.

[30]  Zhiyong Fan,et al.  Ordered arrays of dual-diameter nanopillars for maximized optical absorption. , 2010, Nano letters.

[31]  Dmitri Golberg,et al.  Inorganic semiconductor nanostructures and their field-emission applications , 2008 .