Controlling spin relaxation in 2D hybrid organic-inorganic semiconductors

Abstract

Two-dimensional hybrid organic-inorganic perovskites (2D HOIPs) have emerged as a promising class of semiconductors for next-generation spin-optoelectronic applications, owing to their structural tunability and rich spin-dependent optoelectronic properties. Their layered organic-inorganic architectures also offer opportunities to control spin relaxation via chirality, layer-number tuning, and symmetry engineering. This work discusses how 2D HOIPs can be engineered to manipulate spin dynamics. The first part focuses on quasi-2D chiral perovskites, in which we vary the layer number and uncover how structural confinement governs chiroptical response, spin relaxation, and charge-carrier mobility. The second part highlights inversion-symmetric 2D perovskites, in which local symmetry breaking within the inorganic layers leads to hidden spin-valley locking via functional non-primary ammonium cations. This local structural asymmetry produces large spin splitting and spin-valley textures, which protect optically generated spin-polarized carriers and reveal room temperature spin lifetimes of hundreds of picoseconds in the Pb-based system.