Invited/Optics Frontier Conference: Advanced Photonics

1.Nanyang Technological University

Halide perovskites have recently attracted tremendous attention due to their remarkable properties as an optical gain material, which have shown high performance in solar cells, light-emitting diodes, photodetectors and many other optoelectronic applications. In this talk, I will first review our recent progress in the investigation of halide perovskite materials as excellent optical gain materials, which can be synthesized by either physical or chemical ways. Steady-state and transient spectroscopy approaches can elaborate the large exciton binding energy higher than room temperature thermal excitation energy, and exciton dynamics. High crystalline quality supports the optically pumped photonic lasing based on the intrinsic whispering gallery mode cavity, while the lasing quality factor can be as high as 5000 in all-inorganic perovskite crystals. Next, I will present our experimental realization of room-temperature polariton lasing in all-inorganic cesium lead chloride perovskite crystals embedded in two distributed Bragg reflectors. The perovskite crystals possess efficient polariton-polariton scattering due to the Wannier-Mott exciton nature with large binding energy. The polariton lasing is evidenced by a superlinear power dependence, macroscopic ground state occupation, and increase of the temporal coherence. Finally, we will present our recent results using perovskite materials towards highly efficient light-emitting diode (LED) applications, with a recent record high 20% conversion efficiency in green emission region. This progress also suggests the possibility towards electrically pumped lasing devices.