Directional Laser from Solution-Grown Grating-Patterned Perovskite Single-Crystal Microdisks.

Solution-processed, high-gain, and wavelength-tunable perovskite single-crystal microdisk (PVKsc-MD) lasers have emerged as prospective coherent light sources in advanced nanophotonic designs. However, the inevitable multi-directional emission from a highly symmetrical cavity leads to low light collection efficiency which greatly hinders its application in integrated optical circuits. Here, we report on surface-patterned MAPbBr ₃ PVKsc-MDs synthesized by a cost-efficient bottom-up solution process employing spin-coating and confined-growth nanoimprinting. The patterned microdisks have high crystal quality with regular shape and sharp edges and nano-grating structure on the upper surface. This straightforward process yields surface-patterned PVKsc-MD lasers with a low lasing threshold and high quality (Q) factor. In addition, the grating structure patterned on the PVKsc-MDs reduces the original symmetry of the laser cavity, which improves the emission directionality four times.
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