Potassium fluoride,anhydrous
           Potassium fluoride,extra pure
           Potassium fluoride,Granular
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Hydrofluoric acid is a suitable reagent. Introduction of hydrofluoric acid before and during chemical functionalization of silicon nanocrystals with hydrocarbon chains is found to be very efficient for removing original surface defects of the nanocrystals as well as for preserving them from oxidation induced defects appearing on their surface during photoinitiated hydrosilylation procedure. In consequence, stable sols of highly luminescent silicon quantum dots in organic solvents with photoluminescence quantum yield up to 20% are shown to be easily obtained. Moreover, our approach allows considerable improvement of electric transport through meso-porous silicon nanostructures which is still a serious challenge for their applications in photovoltaics and thermoelectrics. Finally, the use of hydrofluoric acid appears as a cheap and efficient alternative to development of painstaking procedures and set-ups preventing oxidation induced deterioration of physico-chemical properties of the individual and interconnected silicon nanocrystals during their chemical functionalization.

Details of the experiment are as follows: In this letter, we point out that a continuous permanent treatment of Si NCs with hydrofluoric acid (HF) before and during their chemical functionalization with hydrocarbon chains allows not only to efficiently remove original surface defects produced during the fabrication of the NCs by electrochemical etching of bulk Si substrates but also to avoid appearance of the oxidation induced defects on their surface during photoinitiated hydrosilylation procedure. In consequence, (i) considerable improvement of the electric transport through the meso-porous silicon nanostructures has been achieved and (ii) stable sols of highly luminescent Si NCs in organic solvents with PL QY up to 20% are shown to be easily obtained. Experimental results show that  the use of hydrofluoric acid appears as a cheap and efficient reagent.

The second way, called “Hydrofluoric acid-based modified procedure (MP)”, is one-pot synthesis comprised of two consecutive stages: (i) HF-based treatment of the as-prepared Si NCs under UV light and (ii)photoinitiated hydrosilylation reaction in presence of HF acid. Surface chemical modifications of the Si NCs with 1-octadecene and 10-undecylenic acid were carried out in frames of photoinitiated hydrosilylation procedure in two different ways. 

Hydrofluoric acid is very dangerous, laboratory education should develop the habit of marking solution, exposed to the unmarked solution is necessary to use the highest level of protective treatment, generally it refers to hydrofluoric acid. After exposure, please rinse with plenty of water, remove clothing, coated calcium gluconate ointment.