“Liquid Knife” to Fabricate Patterning Single‐Crystalline Perovskite Microplates toward High‐Performance Laser Arrays

A facile and effective "liquid knife" is created by controlling the dewetting process of the liquid precursor, yielding patterning single-crystalline perovskite microplates with uniform size, precise positioning, high quality, and low lasing thresholds. The sizes and location of single-crystalline perovskite are controllable, leading to mode-tunable lasing emission and patterned lasers.