Electric field and strain engineering tuning Rashba spin splitting in quasi-one-dimensional organic–inorganic hybrid perovskites (MV)AI₃Cl₂ (MV = methylviologen, A = Bi, Sb)

Abstract

We systematically study the Rashba spin texture of lead-free quasi-one-dimensional organic-inorganic hybrid perovskites (OIHP) (MV)AI3Cl2(MV = methylviologen, A = Bi, Sb) with first-principles calculation. The k_x-k_y plane Rashba spin splitting...

Crystal Structure and Optical Properties Characterization in Quasi-0D Lead-Free Bromide Crystals (C6H14N)3Bi2Br9·H2O and (C6H14N)3Sb3Br12

“…Negative, zero, and positive values of COHP indicate bonding, nonbonding, and antibonding interactions, respectively. 50 Figure 7c shows the various types of bonds between bismuth atoms and surrounding bromine atoms. The bismuth atom forms individual bonds with six bromine atoms, each with a different bonding stability and strength.…”

“…Consequently, the Rashba energy E VBM = 1.2 meV and E CBM = 19.3 meV were obtained (Figure 8c,d), and the Rashba effect coefficient calculation formula α = 2ΔE/ Δk, 55 the calculated Rashba effect coefficient is α VBM = 60 meV Å and α CBM = 321 meV Å, which is comparable to other organic and inorganic hybrid perovskite materials. 50 The presence of Rashba effect in hybrid perovskite materials reduces the charge carrier dynamics and reveals the magnetooptical property. 56…”

“…The COHP value provides a weighted density of the bond between two adjacent atoms. Negative, zero, and positive values of COHP indicate bonding, nonbonding, and antibonding interactions, respectively Figure c shows the various types of bonds between bismuth atoms and surrounding bromine atoms.…”

“…51,52 Under the symmetric operation of double screw axis, it was determined that the sum of the polarity vector in the direction of the a and c axes is zero, leading to a nonzero polarity along the b axis. 53 The breaking of crystal space inversion symmetry and the large SOC associated with the heavy elements of Bi and Br may promote the Rashba effect. As a result, the degeneracy in k-space could be relieved and the Rashba band splitting is observed from the high symmetry point Z point to G point in the Brillouin zone of CBM and VBM, respectively 50 (Figure 8a,b).…”

“…53 The breaking of crystal space inversion symmetry and the large SOC associated with the heavy elements of Bi and Br may promote the Rashba effect. As a result, the degeneracy in k-space could be relieved and the Rashba band splitting is observed from the high symmetry point Z point to G point in the Brillouin zone of CBM and VBM, respectively 50 (Figure 8a,b). In the absence of SOC, both the valence band maximum and conduction band minimum are located at G point, with a large band gap.…”