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

摘要： Encouraging progresses have 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 effort in developing a high-performance large area cesium lead bromide (CsPbBr3) PeLEDs through a controlled growth of CsPbBr3 emission layer using a hybrid additive in the CsPbBr3 precursor solution. The hybrid additive comprises a combination of poly(ethylene oxide) (PEO) and cesium carbonate (Cs2CO3). We found that the performance of the CsPbBr3 PeLEDs, prepared using the precursor solution having a hybrid additive of PEO and Cs2CO3, is superior to that of the control PeLEDs, prepared using a pure CsPbBr3 precursor solution in two ways: (1) it helps to suppress both the structural defects and non-radiative recombination-induced leakage current, and (2) it assists in improving the electron-hole current balance. The 1.0×1.5 cm2-sized PeLEDs having a maximum luminance of > 104 cd/m2 has been demonstrated, which is more than three times greater than that of a control PeLED prepared using a pure CsPbBr3 precursor solution (3.0×103 cd/m2).