Nanoprinting with Crystal Engineering for Perovskite Lasers

Metal halide perovskites are promising laser light sources due to their exceptional optical gain and solution processability. Structuring the cavity that determines lasing mode and performance, however, is mostly limited to chemical synthesis or in-plane multistep lithographic processes, which lead to high shaping rigidity or poor lasing performance. Here, we introduce a direct electrohydrodynamic three-dimensional printing that produces freestanding, high-performance inorganic perovskite submicro lasers with tailored dimensions and locations, assisted by crystal engineering. The printed vertical nanowires exhibit excellent crystallinity after vapor-phase solvent engineering. Therefore, they show a high-performance two-photon pumped Fabry-Pérot mode vertical lasing with a threshold of 2.98 μJ cm^-2, and our on-demand printing method provides the simplest route to tune the lasing characteristics such as lasing threshold and mode spacing, by adjusting the printed nanowire length. We demonstrated that the length-dependent lasing in the printed arrays can configure multilevel anticounterfeiting labels. We expect this additive manufacturing approach combined with crystal engineering to improve the design flexibility and performance of microphotonic circuitries.