Chemical etching of silicon assisted by graphene oxide

Silicon (Si) nanostructures have received much attention for their use in electronic devices and solar energy conversion. We performed chemical etching of Si(100) covered with graphene oxide (GO). After immersing the sample in a mixture of HF and H2O2 for 4 h or longer, the Si underneath the GO sheets had dissolved more than that in the non-covered area, suggesting that the sheets can be a catalyst for etching reactions. Therefore, the wet chemical method without noble metal catalysts may be another facile and cost-effective method to design Si nanostructures.