n-type Rashba spin splitting in a bilayer inorganic halide perovskite with external electric field

Here, we investigated the Rashba effect of the CsPbBr₃ bilayers under the external electric field (EEF) with first-principles calculations. For the PbBr₂ terminated bilayer, we found that only electrons experience the Rashba splitting under EEF, while holes do not. Such an n-type Rashba effect can be ascribed to the surface relaxation effect that reverses the positions of the top valence bands. The n-type Rashba parameter can be tuned monotonically to the maximum of 0.88 eV Å at EEF of 1.35 V nm^-1 at which the sequence of top valence bands recover to the bulk style. During this process the p-type spins will not survive in this 2D CsPbBr₃, that indeed reveals a new way for making advanced functional spintronic devices.