Bulk inversion asymmetry effect on band structure and optical transition of a new class all-inorganic cubic perovskite nanoplatelet

The band structures at near the R point of all-inorganic cubic CsSnBr3 perovskite nanoplatelets (NPLs) are investigated by using an 8-band k·p method. The Luttinger parameters are given by fitting the first-principles results, the E-K curves and optical transition rule at near the R point are obtained. The bulk invasion asymmetry is taken into consideration in the method. The splitting of energy subbbands is observed at non-R point due to the bulk invasion asymmetry effect, however they are still two-fold degenerated at the R point. The optical transition rule follows the Δn=0 for the thin NPLs, however, for the thicker NPLs, the optical transition rule of Δn=0 does not hold. The results are helpful to understand the cubic perovskite nanoplatelet based spintronics and optoelectronics.