Additive-Stabilized Emission Centers for Blue Perovskite Light-Emitting Diodes.

The performance of the blue perovskite light-emitting diodes (PeLEDs) is limited by the low photoluminescence quantum yields (PLQYs) and the unstable emission centers. In this work, we incorporate sodium bromide and acesulfame potassium into a quasi-2D perovskite to control the dimension distribution and promote the PLQYs. Benefiting from the efficient energy cascade channel and passivation, the sky-blue PeLED has an external quantum efficiency of 9.7% and no shift of the electroluminescence center under operation voltages from 4 to 8 V. Moreover, the half lifetime of the devices reaches 325 s, 3.3 times that of control devices without additives. This work provides new insights into enhancing the performance of blue PeLEDs.