Enhanced Performance of Perovskite Light-Emitting Devices With Improved Perovskite Crystallization

In this paper, we have demonstrated an efficient perovskite light-emitting device (PeLED) by improving perovskite crystallization. The improved perovskite crystallization has been achieved by pretreating the underneath poly (3, 4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) layer with N, N-dimethylformamide (DMF) solvent before single-step spin-coating the perovskite, which results in a prolonged wet environment during the perovskite thermal annealing process to promote the grain growth. The improved perovskite crystallization induces a perovskite thin film with higher surface coverage, fewer defects, and larger grain size with less scattering of grain boundaries. As a result, the PeLEDs exhibit maximum external quantum efficiency of 0.728% and maximum luminance of 2088 cd/m2, which represent a significant improvement over the control devices. Moreover, perovskite films with improved crystalline quality have proved its beneficial effect on the device stability.