The 147-nm Photolysis of Disilane

Article abstract of DOI:10.1021/ja00531a017

The photodecomposition of Si2H6 at 147 nm results in the formation of H2, SiH4, Si3H8, Si4H10, Si5H12, and a solid film of amorphous silicon hydride (a-Si:H).Three primary processes are proposed to accoount for the results, namely, (a) Si2H6 + hν -> SiH2 + SiH3 + H (φ_a=0.61); (b) Si2H6 + hν -> SiH3SiH + 2H (φ_b=0.18); (c) Si2H6 + hν -> Si2H5 + H (φ_c=0.21).The overall quantum yields depend on the pressure but at 1 Torr partial pressure of Si2H6 are Φ(-Si2H6)=4.3+/-0.2, Φ(SiH4)=1.2+/-0.4, Φ(Si3H8)=0.91+/-0.08, Φ(Si4H10)=0.62+/-0.03, Φ(Si,wall)=2.2.Quantum yields for H2 formation were not measured.A mechanism is proposed which is shown to be in accord with the experimental facts.