Photodetached Spin-Polarized Quasi-Free Electrons in Rubidium−Tetrahydrofuran. Dependence of Electron Spin Relaxation upon Wavelength of Excitation

Longitudinal spin relaxation time of electrons photodetached from rubidium anion (Rb - ) in tetrahydrofuran (THF) solution was found to depend on the excitation wavelength (λ = 532, 640, and 720 nm). Spin relaxation rate vs photon energy exhibits a parabolic dependence, which corresponds to the conduction band profile of THF. This unique behavior is attributed to the spin-polarized photoelectrons interacting with rubidium atoms (Rb • ) generated in the same photoprocess. Analysis of the results suggests that the photoelectrons exhibit high mobility, an essential feature for spin injection through interfaces.