Electron scavenging study on the photobleaching of trapped electrons in 3-methylhexane matrices at 77 K

The effect of addition of sulfur hexafluoride as an electron scavenger on quantum efficiency was investigated for the decay of trapped electrons in 3-methylhexane matrices at 77 K during photobleaching in the wavelength range 700 - 1900 nm. Since the quantum efficiency for the decay of trapped electrons in pure matrices is independent of the initial concentration, almost all the recombination of liberated electrons with the cations is geminate. The increase in quantum efficiency for the decay of trapped electrons by the addition of the electron scavenger SF6 was analyzed quantitatively. The quantum efficiency for the photoliberation of trapped electrons from the trapping sites may be about unity. The liberated electrons in the absence of the electron scavenger are retrapped or neutralized. The ratio of the former process to the latter at a wavelength greater than 1500 nm is much larger than that at a shorter wavelength. The wavelength dependence of the ratios of the electron scavenging process to these processes has also been discussed. (auth.)