Two dimensional metal halide perovskites: Promising candidates for light-emitting diodes

Two dimensional halide perovskites are emerging as attractive electroluminescent materials for developing high-performance light-emitting devices owing to their unique structures and/or superior optoelectronic properties. This review begins with an introduction to the working principles of and the key figures for evaluating the performance of LEDs. Secondly, the structure and optoelectronic properties of two dimensional perovskites are summarized and discussed. Their advantages in LED application over their 3D counterparts are systematically analyzed. Following the theoretically discussion, the progresses on the preparation of two dimensional perovskite materials as well as their performances in LEDs have been summarized. At last, several challenges and prospects are presented for achieving high performance 2D perovskite-based LEDs.