Phase Modulation by Vacuum Poling toward Enhanced Performance of Quasi-Two-Dimensional Bromide Perovskite-Based Light-Emitting Diodes.

As a new kind of highly efficient luminescent materials, quasi-two-dimensional (quasi-2D) perovskites show great potential in industrial display applications. In this work, the poling methods are used in modulating the phase arrangement in quasi-2D perovskite light-emitting diodes (PeLEDs). We find the effective modulation of different phase components in uniform arrangement can enhance both brightness and current efficiency to 30 810 cd/m2 and 8.3 cd/A, about 2 times in comparison to results for the control devices. Upon further investigation by optical and impedance spectroscopy, we find the phase modulation can improve the balance of charge carrier injection without sacrificing the transport ability. We believe our studies can provide new inspiration on the influence of phase arrangement in PeLED devices.