Luminescent ordered arrays of nanoporous silicon nanopillars and silicon nanopillars with nanoporous shells

Ordered arrays of nanoporous Si nanopillars and Si nanopillars with nanoporous shells were fabricated using a combination of nanoimprint lithography and metal-assisted chemical etching. They show visible luminescence with an overlap of 2 red emission bands at room temperature. Nanoporous Si nanopillars are formed in highly doped p-Si after metal-assisted chemical etching, while Si nanopillars with nanoporous shells are formed in lightly doped p-Si. The cathodoluminescence intensity is clearly larger in the Si nanopillars with nanoporous shells because they exhibit more luminescence centers at the oxidized surfaces.

► Ordered arrays of Si nanopillars are fabricated using a combination of nanoimprint lithography and metal-assisted chemical etching. ► Nanoporous Si nanopillars (NSN) are fabricated from highly doped Si. ► Si nanopillars with nanoporous shells (SNS) are fabricated from lightly doped Si. ► Both NSN and SNS show a luminescence effect with red emission bands.