Sonochemistry of silicon hydrides

Silicon hydrides (silanes) are key precursors for electronic- and solar-grade silicon and silicon nanoparticles, and are used in various other applications. Conversion of silanes to Si and hydrogen is an energy-intensive process. For example, epitaxial Si production from silanes or Si colloid production requires high temperatures (many hundred kelvin), high pressures (a few hundred bar), or both (1), which is a cost driver and limits the growth rates in methods such as chemical vapor deposition. Although trisilane (Si3H8) allows an order-of-magnitude higher Si deposition rate for semiconductor applications when compared to SiH4 at comparably low temperatures, down to ∼400°C (2), solution processing of silanes (3, 4) is desirable to avoid high vacuum, temperature, and pressure. In a series of studies, Cádiz Bedini et al. (5–8) have shown that applying ultrasound to liquid silicon hydrides such as Si3H8 and cyclopentasilane (Si5H10) opens a path toward tunable synthesis of silicon nanoparticles, silicon polymers, as well as higher silanes at ambient temperature and pressure conditions.