Wuhan Optoelectronics Forum No.166 was successfully held in the form of live stream online meeting in the morning of June 28. Professor Xiong Qihua from Nanyang Technological University delivered an exciting presentation entitled ‘Exciton Polariton Lattices in Halide Perovskite Semiconductors’. Professor Zhang Xinliang, Vice President of Huazhong University of Science and Technology (HUST), chaired the forum, and awarded the forum medal to Professor Xiong Qihua.
Exciton polaritons are part-light, part-matter strongly interacting Bosonic quasiparticles by dressing excitonic resonances with microcavity photons. They have extremely light effective mass and strong nonlinearity, which have shown tremendous potential in quantum fluid of light (i.e., Bose-Einstein condensate of polaritons), ultrafast polaritonic switching and topological polaritonics. Over the past several decades, this field has been largely fuelled by high quality II-VI (e.g., CdTe) or III-V (e.g., GaAs) quantum wells operating at only cryogenic temperatures constrained by the small exciton binding energy. Some organic materials show promising operation at room temperature, nonetheless they usually suffer from large threshold density and weak nonlinearity. In this talk, Professor Xiong introduced their recent progress in realizing exciton polariton condensate and lasing in a few halide perovskite semiconductors. Then he showed that they can further optically manipulate the condensate by introducing 1D artificial polariton lattices with a large forbidden bandgap opening up to 13 meV. This work further opens a diverse possibility of 2D polariton lattices and network towards quantum simulator and topological lasing. Finally, he showed some perspective work in 2D lattices, new type of band structures and polaritonic devices.