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 multi-step 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 sub-micro 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 multi-level anticounterfeiting labels. We expect this additive manufacturing approach combined with crystal engineering to improve the design flexibility and performance of micro photonic circuitries.