| 초록 |
Electrophoretic Deposition and spin-coating methods with dilluted quantum dot(QD) are compared at 85nm thickness emissive layer(EML) deposition. To compare two methods, we used CdSe@ZnS, CdSe@ZnS/ZnS QD and QD-based light emitting diod(QLED) structure, where the QD-EML is sandwiched by 4,4′-Bis(N-carbazolyl)-1,1′-biphenyl and ZnO nanoparticles as hole and electron-transport layers respectively. We find LED which used EPD on EML has higher external quantum efficiency(EQE) than LED which used spin-coating. Compared to spin-coating-used devices the EQE of EPD-used devices was higher, specifically showing values of peak current efficiency of 9.2cd/A and EQE of 2.09%. Such results' gap is likely attributable to imporoved interlayer interaction via EPD which can make better quality of EML : more even, less carrier trap sites. Also in comparing CdSe@ZnS, dSe@ZnS/ZnS QDs, we find additional shelling is able to make higher EQE. |
