Optimization of Fluorescent Silicon Nanomaterial Production Using Peroxide/Acid/Salt Technique

Silicon nanomaterial was prepared using the peroxide/acid/salt technique in which an aqueous silicon-based salt solution was added to H2O2/HF etchants. In order to optimize the experimental conditions for silicon nanomaterial production, the amount of nanomaterial produced was studied as a function of the volume of the silicon salt solution used in the synthesis. A set of samples was prepared using: 0, 5, 10, 15 and 20 mL of an aqueous 1 mg/L metasilicate solution. The area under the corresponding peaks in the infrared (ir) absorption spectra was used as a qualitative indicator to the amount of the nanomaterial present. The results indicated that using 10 mL of the metasilicate solution produced the highest amount of nanomaterial. Furthermore, the results demonstrated that the peroxide/acid/salt technique results in the enhancement of the production yield of silicon nanomaterial at a reduced power demand and with a higher material to void ratio. A model in which the silicon salt forms a secondary source of silicon nanomaterial is proposed. The auxiliary nanomaterial is deposited into the porous network causing an increase in the amount of nanomaterial produced and a reduction in the voids present. Thus a reduction in the resistance of the porous layer and consequently reduction in the power required, are expected.