Surface Characterization of Hydrogenated Silicon Powder Made by the Laser-Induced Decomposition of Silane

Silicon particles formed by the laser-driven decomposition of silane have a hydrogenated surface, a product of the forming process. The IR spectrum of this powder has much narrower bands than are found in hydrogenated amorphous silicon. In particular, it has a band at 2,094 cm{sup {minus}1} assignable to SiH{sub 2} and a band at 2,080 cm{sup {minus}1} assignable to SiH; hydrogenated amorphous silicon has a single band at 2,100 cm{sup {minus}1}. Changing the bonding environment of the surface hydrogen by controlled oxidation of the particles results in a slight broadening of the Si-H absorption band and the formation of oxidized Si-H absorption bands at higher frequencies.