Survival coefficient of Ga(5s2S1/2) sputtered from a GaAs surface

Abstract The effect of ambient oxygen gas on the survival probability for an excited Ga(5s) atoms to escape from a mono-crystalline GaAs (100) crystal without suffering tunneling de-excitation was investigated from measurements of photons emitted through the 5s 2 S 1/2  → 4p 2 P 3/2, 1/2 transition (417.20 nm, 403.3 nm lines) by Ar + bombardment using optical spectroscopic technique. A Doppler analysis of the emitted line profile under an oxygen-free condition gave A / a  = (5.2 ± 0.6) × 10 4  m/s. The transition rate for the resonant de-excitation of Ga(5s) was estimated as R  ∼ 1.8 × 10 13  s −1 at atom-surface distance of 2 × 10 −10  m. The experimental result obtained was discussed in connection with the light-intensity dependence of the 417.2 nm spectral line on the distances from the target surface. The experimental result on the ambient oxygen gas effect was also discussed.