Whispering Gallery Mode Lasing from Self-Assembled Hexagonal Perovskite Single Crystals and Porous Thin Films Decorated by Dielectric Spherical Resonators

Lasing in self-assembled hybrid organic inorganic lead halide perovskites semiconductors has attained intensive research for low cost and high performance optoelectronic devices due to their inherent outstanding optical response. However, to achieve the controllable laser action from a small single crystal remains as a challenging issue. Here, we present a novel technique to fabricate self-assembled high-quality hexagonal perovskite single crystals for realizing room-temperature near infrared whispering-gallery-mode (WGM) laser action. Quite interestingly, the lasing spectrum for an individual CH3NH3PbI3 hexagonal single crystals encompasses the aspects of high quality factor (Q) and low threshold WGM lasing around 1200 and 26.8 mu J/cm(2), respectively. In addition, we demonstrate that when the porous perovskite thin films were decorated with dielectric spheres, the laser oscillation can be achieved through the coupling of WGM with perovskite gain material. We found that the lasing spectra can be well manipulated by the size of hexagonal single crystals and SiO2 spheres. Moreover, the discovered laser action and chemical stability of hexagonal single crystal perovskites not only render them significant practical use in highly efficient near-infrared emitting devices for laser photonics, solid-state lighting, and display applications, but also provide a potential extension toward various optoelectronic devices.