Silicon nanoparticles with UV range photoluminescence synthesized through cryomilling induced phase transformation and etching

We report silicon nanoparticles with a particle size distribution of similar to 80 nm (mode) through controlled impact mode cryomilling of semiconductor grade silicon wafers at a temperature of 200 K under argon atmosphere. The transmission microscopic characterization of these particles establishes a partial transformation of the crystalline silicon into an amorphous phase yielding a two-phase microstructure for each of the particles. A high-speed imaging technique is utilized to understand the effect of impact energy (and milling intensity) on the phase transformation during milling. In a further development, etching of the two-phase nanocomposites leads to the dissolution of the amorphous phase yielding free nanoparticle of similar to 2 nm size that exhibit UV range photoluminescence with potential for sensors and other optical applications.

Automated summary

Silicon nanoparticles with a particle size distribution of around 80 nm were successfully obtained through controlled impact mode cryomilling of semiconductor grade silicon wafers. The microstructure analysis revealed a two-phase structure in each particle, with the crystalline silicon partially transformed into an amorphous phase. Further etching of the two-phase nanocomposites resulted in the dissolution of the amorphous phase, producing free nanoparticles of approximately 2 nm in size that exhibited UV range photoluminescence and showed potential for sensors and other optical applications.