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Published online: 24 March 2010 | doi:10.1038/nchina.2010.40

Thin films: A quantum-dot stencil

Felix Cheung

Introduction

© (2010) Wiley Interscience

There are several methods for making large-scale nanopatterns on substrates. One commonly used method is to place an ultrathin alumina membrane (UTAM) with nanosized holes on a substrate and then fill the holes with the desired material — here, the UTAM simply acts as a template for nanostructures to grow.

Yong Lei and co-workers at Shanghai University in China and the University of Münster in Germany¹ have now prepared a UTAM with quantum-sized holes. The UTAM is ideal for fabricating large-scale quantum-dot arrays, which are highly sought after in optoelectronics and display devices.

Preparation of the arrays involves a two-step anodization process using a lower current, weaker acid and lower temperature for etching than traditional anodization processes. The milder conditions result in a much lower growth rate, and because of this, the researchers were able to grow an 80-nanometre-thick UTAM with quantum-sized pores on a silicon substrate.

Using this UTAM, the researchers were able to prepare an ordered array of gold quantum dots with diameters of about 20 nanometres. The area of the UTAM is about two square centimetres, and the technique can be scaled up for the fabrication of larger arrays.

The authors of this work are from:
Institute of Nanochemistry and Nanobiology, School of Environmental and Chemical Engineering, Shanghai University, Shanghai, China; Institute of Materials Physics and Center for Nanotechnology, University of Münster, Münster, Germany.

Reference

1. Wu, M. et al. Ultrathin alumina membranes for surface nanopatterning in fabricating quantum-sized nanodots. Small 6, 695–699 (2010).  | Article | PubMed | OpenURL | | ChemPort |