Large-Area Cesium Lead Bromide Perovskite Light-Emitting Diodes Realized by Incorporating a Hybrid Additive

Encouraging progress has been made in the development of solution-processable perovskite light-emitting diodes (PeLEDs). However, the related fundamental physics of the efficient operation of the large-area PeLEDs is still far from adequate. In this work, we report our recent efforts in developing a high-performance large-area cesium lead bromide (CsPbBr 3 ) PeLEDs through a controlled growth of the CsPbBr 3 emission layer using a hybrid additive in the CsPbBr 3 precursor solution. The hybrid additive comprises a combination of poly(ethylene oxide) (PEO) and cesium carbonate (Cs 2 CO 3 ). We found that the performance of the CsPbBr 3 PeLEDs, prepared using the precursor solution having a hybrid additive of PEO and Cs 2 CO 3, is superior to that of the control PeLEDs, prepared using a pure CsPbBr 3 precursor solution in two ways: (1) it helps to suppress both the structural defects and nonradiative recombination-induced leakage current and (2) it assists in improving the electron–hole current balance. The 1.0 × 1.5 cm 2 -sized PeLEDs having a maximum luminance of >10 4 cd/m 2 have been demonstrated, which is more than three times brighter than that of a control PeLED prepared using a pure CsPbBr 3 precursor solution (3.0 × 10 3 cd/m 2 ).