Title: Room Temperature Polariton Lasing in All-Inorganic Perovskites,
Abstract: Polariton lasing is the coherent emission arising from a macroscopic
polariton condensate first proposed in 1996. Over the past two decades,
polariton lasing has been demonstrated in a few inorganic and organic
semiconductors in both low and room temperatures. Polariton lasing in inorganic
materials significantly relies on sophisticated epitaxial growth of crystalline
gain medium layers sandwiched by two distributed Bragg reflectors in which
combating the built-in strain and mismatched thermal properties is nontrivial.
On the other hand, organic active media usually suffer from large threshold
density and weak nonlinearity due to the Frenkel exciton nature. Further
development of polariton lasing towards technologically significant
applications demand more accessible materials, ease of device fabrication and
broadly tunable emission at room temperature. Herein, we report the
experimental realization of room-temperature polariton lasing based on an
epitaxy-free all-inorganic cesium lead chloride perovskite microcavity.
Polariton lasing is unambiguously evidenced by a superlinear power dependence,
macroscopic ground state occupation, blueshift of ground state emission,
narrowing of the linewidth 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.