Multimode exciton-polaritons in self-assembled hybrid organic-inorganic perovskite microcavities

Title : Multimode exciton-polaritons in self-assembled hybrid organic-inorganic perovskite microcavities

Abstract:

The control of coherent light–matter interactions within semiconductor microcavities is fundamental to the realization of next-generation solid-state polaritonic devices. Hybrid inorganic–organic perovskites, particularly CH?NH?PbBr?, have emerged as promising material platforms for room- temperature polaritonics due to their high exciton oscillator strength and substantial exciton binding energies. In this study, we demonstrate strong exciton–photon coupling in self-assembled CH?NH?PbBr? microcavities with micro-platelet (MP) and micro-ribbon (MR) geometries. Owing to their distinct dimensional configurations, the MP structure behaves as a vertical Fabry–Pérot (FP) microcavity, while the MR forms an in-plane FP cavity. Angle-resolved photoluminescence (ARPL) mapping reveals the formation of multimode exciton–polaritons (MEPs), with the lower polariton branches well described by the coupled oscillator model. From these fittings, we extract large vacuum Rabi splittings of approximately 205 meV and 235 meV for the MP and MR structures, respectively. Notably, the ARPL data from the MR configuration, measured along the cavity axis, exhibit a clear Young’s double-slit-like interference pattern. Supported by numerical simulations, this observation enables unambiguous identification of the parity and mode order of the cavity modes contributing to the MEP formation. These findings not only provide compelling evidence of strong light–matter coupling in novel CH?NH?PbBr? microcavity architectures but also pave the way for the development of advanced polaritonic devices operating at ambient conditions.

Biography:

Dr. Y. S. Kim is a Professor in the Dep. of Semiconductor Engineering at the University of Ulsan, Korea. Dr. Kim earned his Ph.D. in Semiconductor Physics from Seoul National University in 1998 and has since dedicated his career to advancing semiconductor science and education. Before joining academia, he spent a decade at SK-Hynix Semiconductor Inc. as a principle researcher, where he contributed to the development of high-performance memory devices, including dual-poly metal gate and high-performance ALD technologies. His academic research focuses on 2D transition metal dichalcogenides (TMDCs), valleytronics, polaritons, and neuromorphic memory devices. He has led multiple national research projects funded by the NRF and KEIT of Korea, so on, emphasizing next-generation optoelectronics and green energy materials. His recent publications cover topics such as strong exciton-photon coupling, valley polarization in 2D materials, and microcavity design.