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Abstract
Hybrid organic-inorganic perovskites (HOIPs) are rapidly emerging as functional materials for novel optoelectronic and quantum electronic devices. Recently, the power conversion efficiency for a single-junction HOIPs based solar cell having an analog of MAPbI3 (where MA = CH3NH3) as the absorber layer exceeded 26%. The high-power conversion efficiency observed for these materials may be related to the degree of spin-orbit coupling (SOC) strength present in their crystal structure. It has been hypothesized that the breaking of structural and bulk inversion symmetry in combination with the strong intrinsic spin-orbit coupling (SOC) from heavy Pb atoms in the superlattice gives rise to large Rashba-Dresselhaus SOC, where spin-dependent properties can be manipulated by electric fields. In this dissertation, I will present my study on Rashba-Dresselhaus SOC in 3D (MAPbI3) and 2D Ruddlesden-Popper perovskite superlattices (BA)2MAn-1PbnI3n+1 with n = 1, 2, and 3 (where BA = CH3(CH2)3NH3). I have utilized several experimental techniques to investigate the spin-dependent processes in HOIPs including (i) magnetic field effect (MFE) in electroluminescence and conductivity of HOIPs-based light-emitting diodes (LEDs), where the Rashba-Dresselhaus SOC strengths versus applied electric fields are measured, (ii) circular dichroism (CD) and circularly polarized luminescence (CPL) spectroscopies on HOIP thin films in which the degeneracy lifting of the electronic ground states and excited states by the Rashba-Dresselhaus field can be measured by CD and CPL spectroscopies, respectively. We found that the Rashba-Dresselhaus SOC is very large in 2D Ruddlesden-Popper perovskite (BA)2MAn-1PbnI3n+1 when n = 1 and n = 2 and monotonically decreases as n increases. (iii) Finally, I will study and elucidate the energy transfer and energy upconversion processes between the MAPbI3 perovskite and rubrene singlet fission molecules C42H28 by the magnetic field effect on photoluminescence (MPL). Our studies may have a significant impact on future development of electrically-controlled spin logic devices via Rashba-Dresselhaus effects and high-performance solar cells.