Solution-Processed Large-Scale Concentric-Ring Laser On Two-Dimensional Ruddlesden-Popper Perovskites Thin Films

Self-assembly of large-scale periodic structures is promising for the applications of optoelectronic devices and enhancing light trapping or extraction in optoelectronics. Spontaneous pattern formation provides a facile and large-area fabrication technology for ordered concentric-ring patterns. Herein, a facile and robust solution-processed method for the controllable spontaneous formation of concentric-ring patterns on 2D Ruddlesden-Popper perovskite (2D-RPP) thin films is presented. High-quality (sub)millimeter-scale concentric multi-rings are prepared and their parameters can be adjusted by experimental conditions. The obtained 2D-RPP concentric-ring patterns show excellent lasing behaviors with high-quality factor and significantly low lasing threshold. This strategy can be exploited for the development of high-performance 2D-RPP laser arrays and the integration of optoelectronic devices.