Probing charge transfer processes at p-GaAs electrodes under weak optical excitation

Spin-dependent charge transfer at chiral electrodes probed by magnetic resonance

“…In the case of optically pumped p-GaAs, we find a relative spin-dependent charge transfer rate difference (eqn ( 6)) of only 2 to 5%, with a possible complication due to the presence of surface states. 38 When using Al5 chiral molecules, we have found a strong spin dependence, indicating a spin-polarization after passing the chiral molecules of 6 to 19%, which is consistent with the idea that chiral molecules act as spin filters.…”

“…This dark process is likely to originate from the valence band, with a hole transfer mediated by surface states. 38 A laser light power of 80 mW was chosen to maximize the current while staying away from the diffusion-limited regime.…”

“…At the p-GaAs surface, surface states are to be expected, which can accept additional electrons. 38 These surface states can act as additional intermediate transfer states, ultimately leading to a slower transfer or even spin trapping. Chiral molecules, in contrast, suppress dangling bond terminations.…”