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Qihua Xiong1

1, Nanyang Technological University, Singapore, , Singapore

Perovskite materials have recently attracted considerable interest in photovoltaics and light-emitting diodes. In general, a number of hybrid and all-inorganic perovskite materials are excellent optical gain materials, due to strong optical absorption, large exciton binding energy and oscillator strength. In this talk, I will first discuss our effort in vapor phase synthesis of high quality inorganic-organic or all-inorganic perovskite crystals, with controllable emission band from ultraviolet to near-infrared. Steady-state and transient spectroscopy approaches can elaborate the exciton binding energy and excitonic emission nature at room temperature. Then I will discuss the optically pumped photonic lasing based on the intrinsic whispering gallery mode cavity will then be presented, while the lasing quality factor can be as high as 5000 in all-inorganic perovskite crystals. Lastly, I will introduce our latest work on room temperature exciton-polariton lasing in all-inorganic perovskite CsPbCl3 crystals embedded in optical microcavities. Those crystals have exceptionally large exciton binding energy, strong oscillator strength and can be grown by facile epitaxy-free techniques. Polariton lasing is unambiguously evidenced by a superlinear power dependence, macroscopic ground state occupation, blueshift of ground state emission, and the build-up of long-range spatial coherence. Our work suggests considerable promise of lead halide perovskites towards large-area, low-cost, high performance room temperature polariton devices and coherent light sources extending from the ultraviolet to near infrared range.

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