(669e) Extending Spin-Dephasing Lifetimes in Metal-Halide Perovskites By Morphology Engineering

Inorganic metal-halide perovskites have emerged as a promising platform for quantum information and spintronic applications, due to their large spin-orbit coupling, high photoluminescence quantum yields, photostability, and optical spin selection rules. Specifically, CsPbBr₃ nanocrystals also exhibit long optical coherence times and short photoluminescence lifetimes, marking metal-halide perovskites as enticing single-photon emitters. For quantum information and spintronic devices, metal-halide perovskites materials also require long inhomogeneous spin-dephasing time (T₂*), for reliable initialization, transport, manipulation, and read out spins. Recently, we demonstrated that CsPbBr₃ nanocrystals exhibit photoluminescence lifetime-limited hole spin dephasing and we predicted that tuning geometry could significantly extend hole dephasing lifetime to potentially enable this exciting class of materials for spin-based applications.

Here, we use time-resolved Faraday rotation to study the inhomogeneous spin dephasing dynamics in CsPbBr₃ thin films for this first time and quantify the impact of morphology. Combining temperature and magnetic field dependent time-resolved Faraday rotation and photoluminescence, we describe a cohesive mechanism for spin dephasing in CsPbBr₃. Leveraging these results, we engineer photoluminescence lifetime limited T₂* in CsPbBr₃ thin films. These measurements initiate metal-halide perovskite nanomaterials for spintronic and quantum-information applications and provide design rules for the future development of inorganic and hybrid metal-halide perovskites