Yujing Bi’s Nature Electronics: Over 16% Record Efficiency! Quasi-Two-Dimensional Perovskite Blue Light-Emitting Diode

Perovskite light-emitting diodes hold tremendous potential for advancing color displays and solid-state lighting, which in turn calls for high-performance blue perovskite emission. However, due to poor charge injection at the interface between the hole-injection layer and the perovskite film, extensive nonradiative recombination, and random phase distribution, quasi-2D blue perovskite LEDs exhibit lower performance compared with their green and red counterparts.

Research by You Jingbi and colleagues at the Institute of Semiconductors, Chinese Academy of Sciences, demonstrates that adding an alkali metal salt (cesium chloride) to the hole-injection layer—poly(3,4-ethylenedioxythiophene) polystyrene sulfonate—can enhance carrier transport within the injection layer. The study found that this approach leads to a more favorable band alignment, thereby successfully improving the charge-injection efficiency of perovskite materials.

Furthermore, the growth of the perovskite layer on a cesium chloride-doped substrate also induces a reorganization of its phase distribution, resulting in reduced non-radiative recombination and enhanced charge transport. Based on this approach, the researchers fabricated a sky-blue quasi-2D perovskite light-emitting diode with an emission peak at 486 nm, a peak external quantum efficiency of 16.07%, and excellent operational stability.