Tunable luminescence of nanoporous silicon via electrochemical etching parameters

This paper reports the surface state induces a variation in light emission of nanoporous Si as a function of electrolyte condition, anode-cathode distance and aging in common chemical reagents to achieve strong and stable luminescence of Si semiconductor. The electrochemical derived nano Si was observed to have a nanoporous structure with the pore of about 20 nm in the thickness of 50 μm. The luminescence of nanoporous Si was showed enhancing in the sample with the HF/ethanol of 1:1 and the anode-cathode distance of about 5 cm. As etched specimen, the luminescence of the nanoporous Si was centered at 800 nm; however blue-shift when they were immersed in green chemical reagents. These results suggest that the potential application of electrochemical etching followed by green chemical treatment to tunable luminescence, which was potential application in nanoporous Si based devices and nanomedicine.