High-Performance Quasi-Two-Dimensional CsPbBr2.1Cl0.9:PEABr Perovskite Sky-Blue LEDs with an Interface Modification Layer

This paper elucidates the increased luminescence efficiency of CsPbBr 2.1 Cl 0.9 sky-blue perovskite light-emitting diodes (PeLEDs) achieved through the interface modification of 3,4 ethylenedioxythiophene (PEDOT):polystyrene sulfonic acid (PSS)/quasi-two-dimensional (QTD) perovskite using CsCl and CsBr materials, respectively. QTD films were fabricated using ratios of CsPbBr 2.1 Cl 0.9 doped with phenethylamine hydrobromide (PEABr) at 60%, 80%, and 100%. The solvent dimethyl sulfide (C 2 H 6 OS) was employed under the excitation of ambient and 365-nm laser lights. The PeLED structure was composed of Al/LiF/2,2',2"-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi)/CsPbBr 2.1 Cl 0.9 :PEABr/interface modification layer/PEDOT:PSS/ITO glass. The optimized results revealed that the luminance, current efficiency, and external quantum efficiency of the QTD CsPbBr 2.1 Cl 0.9 :80% PEABr PeLED with the CsCl interface modification additive was 892 cd/m 2 , 3.87 cd/A, and 5.56%, respectively.