Study On Performance Of PeLED Device Based On CsPbBr₃ Composite Film

At present,the study of PeLED device has made great progress,however,compared with OLED devices,the stability and efficiency of PeLED still have a lot of room for improvement,and the device lifetime cannot meet the requirements of practical applications.This paper starts with improving the morphology of CsPbBr₃film and promoting the balance of cation-anode carrier injection to improve the performance of PeLED devices.The specific plan is as follows:Firstly,the Lewis base mCP is added to the all-inorganic perovskite CsPbBr₃,the quality of the perovskite film is effectively improved by the solid phase chemical reaction of the two.While CsPbBr₃:mCP=1:0.1,the optimal PeLED device is turned on3V,brightness is 21008cd/m²,current efficiency and external quantum efficiency are3.74cd/A and 1.21%,which demonstrates the positive effect of organic small molecule assisted method on the performance of PeLED devices.Secondly,an appropriate amount of organic molecule mCP is doped in CdSe/ZnS.Small molecules can effectively fill the voids of quantum dots and improve the quality of the light-emitting layer.The optimal device brightness is 10698cd/m²,which is 2.0times higher than that of the basic device.The maximum current efficiency is 18.1cd/A,which is about 1.8 times higher than that of the basic device,which proves the feasibility of the small molecule assisted method.Furthermore,the hole transporting material PVK is doped in CsPbBr₃,so that CsPbBr₃ is embedded in the three-dimensional network structure of the polymer to effectively enhance the morphology of the perovskite,and the optimum device brightness is increased from 2339cd/m² to 4266cd/m².It effectively proves the feasibility of polymer cross-linking in PeLED devices.Finally,the influence of the introduction of the cathode Al₂O₃ film and the formation of the interfacial layer of Al₂O₃ on the performance of the PeLED device was investigated.Experiments show that Al₂O₃ treatment can effectively eliminate carrier-balanced injection.Compared with the reference group,the maximum brightness of pure CsPbBr₃ PeLED device is increased from 2064cd/m² to 2801cd/m²,EQE is increased from 0.81%to 1.08%;CsPbBr₃:mCP PeLED device is the largest.The brightness increased from 21,008cd/m² to 23,313cd/m²,and the EQE increased from1.21%to 1.50%.