Title: Hybrid Perovskite Spintronics

Researchers have shown that hybrid organic-inorganic perovskites (or organometal trihalide perovskites) are not only aimed to be used in solar cell applications but also pursue a vast variety of fundamental research directions. One of the growing topics is the understanding of photo-physics and spin-related properties in hybrid perovskites since they play a major role in the processes of carrier photogeneration and carrier transport, which are the corner stone’s of photovoltaic applications, as well as in other optoelectronic applications. In this talk, we will discuss the spin-optoelectronic and magnetic properties of these solution-processed hybrid materials and their fundamental spin-dependent physical behavior: (i) We will talk about the observation of spintronic-Terahertz (THz) radiation in layered Pb-based hybrid perovskites interfaced with a ferromagnetic metal, produced by ultrafast spin current under femtosecond laser excitation. Due to the presence of the pronounced Rashba splitting state in Pb-based hybrid perovskites, the generated THz radiation exhibits an asymmetric intensity toward forward and backward emission direction whose directionality can be mutually controlled by the direction of the applied magnetic field and linear polarization of the laser pulse. (ii) We will show that the Dzyaloshinskii–Moriya-Interaction (DMI), a chiral antisymmetric interaction that occurs in magnetic systems with low symmetry, can be presented in layered magnetic hybrid perovskites of which the metal site, Pb is replaced by Cu. We show that layered Cu-based hybrid perovskite antiferromagnets with an interlayer DMI will lead to a strong intrinsic magnon-magnon coupling strength up to 0.24 GHz, which is four times greater than the dissipation rates of the acoustic/optical magnonic modes. Our work shows that the DMI in these hybrid antiferromagnets holds promise for leveraging magnon-magnon coupling by harnessing symmetry breaking in a highly tunable, solution-processable layered magnetic platform.

Dali Sun, NCSU

Dr. Sun’s research interests are in spintronics and optoelectronics of organic semiconductors, magnetic thin films, and organic-inorganic hybrid perovskites. It includes the studies of organic spin valves, organic light-emitting diodes, hybrid perovskite optoelectronic/spintronics devices, and their device physics. The Sun Research Group at NC State focuses on exploring novel routes for spin injection and detection, magnetic field effect, spin Hall effect and their applications in molecules, polymers and newly emerged materials. Dr. Sun is one of the pioneers who launched spintronic studies in hybrid perovskite materials.