Collisional behaviour of electronically excited silicon atoms, Si(3p2(D1D2)), by atomic absorption spectroscopy

✍ Scribed by D. Husain; P.E. Norris

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 467 KB
• Volume: 53
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(78)80051-7

✦ Synopsis

The collisional behaviour of electronically excited silicon atoms in the opticalIy metastable 3p2 (ID*) state (0.781 eV) is imestigated by time-resolved resonance absorption in the ultraviolet. Si(3 '9) was generated by the repetitive pulsed irmdiation of Sic14 at & > 165 nm in a flow system, and monitored by attenuation of resonance radiation at h = 288.16 nm (4s(' Pp) + 3p* (t Dz)) using signal averaging Absolute second-order rate constants (kR, cm3 molecule-' s-l, 300 ICI are reported for the gases. Hz [(S-l c 1.5) X lO_"]. O2 [(2.3 f 0.4) X 10-l' 1, He (=Z 10-t5) and Sic14 [(2.9 -c 0.4) X 10-t"l. These results are compared with the analogous data reported hitherto for S1(3 3P~) and Si(3 'So>_ Those for Hz and 02 are discussed within the context of symmetry arguments on the nature of the potential surfaces involved using the weak spin orbit coupIing approximation. Finally, pulsed stimulated emission operating on the.transition Si(3p*)(tSo + 1 D2) (h = 1.0995 p) was not detected in high energy pulse experiments usmg a confocal cavity, despite the population inversion between Sic3 'So) and %(3 'D-,) observes by resonance absorption following the photolysis of Sick.