Formation of Lead Halide Perovskite Based Plasmonic Nanolasers and Nanolaser Arrays by Tailoring the Substrate.

Hybrid plasmonic nanolasers are intensively studied due to their nanoscale mode confinement and potentials in highly integrated photonic and quantum devices. Until now, the characteristics of plasmonic nanolasers are mostly determined by the crystal facets of top semiconductors, such as ZnO nanowires or nanoplates. As a result, the spasers are isolated, and their lasing wavelengths are random and difficult to tune. Herein, we experimentally demonstrate the formation of lead halide perovskite (MAPbX) based hybrid plasmonic nanolasers and nanolaser arrays with arbitrary cavity shapes and controllable lasing wavelengths. These spasers are composed of MAPbX perovskite nanosheets, which are separated from Au patterns with a 10 nm SiO spacer. In contrast to previous reports, here, the spasers are determined by the boundary of Au patterns instead of the crystal facets of MAPbX nanosheets. As a result, whispering gallery mode based circular spasers and spaser arrays were successfully realized by patterning the Au substrate into circles and gratings, respectively. The standard wavelength deviation of spaser arrays is as small as 0.3 nm. Meanwhile, owing to the anion-exchangeable property of MAPbX perovskite, the emission wavelengths of spasers were tuned more than 100 nm back and forth by changing the stoichiometry of perovskite postsynthetically.