High Purity Porous Silicon Powders

High Purity Porous Silicon:
Porous Silicon powders come in two varieties.  The first variety are very pure >99.99% Si particles that have been electrochemically etched using HF and a solvent.  Pore sizes are uniformly controlled during the etching process and can be finely tuned depending on the desired outcome.

Metallurgical Si:
The second variety, similar in function to the electrochemically etched pure Si, but has been optimized to be cost effective. By using metallurgic Si, with a purity of roughly 91% Si, and an electroless chemical etching process the Price per gram can be drastically reduced.  Unfortunately with this chemical etching process the overall limits of the method results at around 50% porosity.  

Particle Sizes

Typical particle sizes range from 20-150µm.  Depending on volume, etching parameters and application requirements the particles can also be reduced in the sub-micron and nanoparticle regimes.

Typical porosity ranges are between 40% and 75% for electrochemical etching and upto 50% for electroless etching.

For customized material, tests can be done to find the correct balance between pore diameter and overall porostiy.