Unravelling Rashba Effect through Spin Texture Evolution in Uni-Dimensional Confined Halide Perovskite under Compression

The pursuit of uni-dimensional hybrid halide perovskites holds significant importance in the field of spin-optoelectronics due to quantum confinement effect. Moreover, such confined systems with constituent heavy elements (Pb,Bi, etc) could be prone to Rashba effect considering relativistic spin-orbit coupling (SOC) and inversion symmetry breaking. The repercussion of Rashba splitting could be very well reflected in charge carrier recombination rate, which is significant for manifesting efficient photovoltaic devices. One way to manipulate such recombination rate is through tuning the Rashba splitting corresponding to the spin texture of such materials under the external pressure or structural compression. In this work, we have envisaged such evolution paradigm in one of the promising non-centrosymmetric hybrid halide perovskite through rigorous electronic structure calculations. The electronic and optical properties along with the Rashba splitting and spin texture are being systematically observed within the thermodynamic limit of under compression equivalent to 9.6 GPa in this promising halide perovskite. Our study successfully reveals the intriguing transition of electronic band structure from indirect to a direct bandgap phenomena under compression in addition to an interesting red shift in the optical absorption spectra. To accurately describe the spin polarization both in-plane and out-of-plane, we have explored a three-dimensional Rashba model. The in-plane spin-texture has been found to arise from the octahedral distortion along the b-direction. The fundamental interplay between structural distortions and the Rashba-splitting in the considered one-dimensional system under the influence of compression along with the evolution of spin texture could very much hold potential for the pursuit of sustainable energy.