DAYOUNG LEE Kim, Hong Hee ROH JI HYOUN Lim Keun Yong Park, Donghee Lee, In-Han CHOI, WON KOOK 2024-01-12T03:30:20Z 2024-01-12T03:30:20Z 2022-06-15 2022-06 2079-4991 https://pubs.kist.re.kr/handle/201004/76706 The widely used ZnO quantum dots (QDs) as an electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs) have one drawback. That the balancing of electrons and holes has not been effectively exploited due to the low hole blocking potential difference between the valence band (VB) (6.38 eV) of ZnO ETL and (6.3 eV) of CdSe/ZnS QDs. In this study, ZnO QDs chemically reacted with capping ligands of oleic acid (OA) to decrease the work function of 3.15 eV for ZnO QDs to 2.72 similar to 3.08 eV for the ZnO-OA QDs due to the charge transfer from ZnO to OA ligands and improve the efficiency for hole blocking as the VB was increased up to 7.22 similar to 7.23 eV. Compared to the QLEDs with a single ZnO QDs ETL, the ZnO-OA/ZnO QDs double ETLs optimize the energy level alignment between ZnO QDs and CdSe/ZnS QDs but also make the surface roughness of ZnO QDs smoother. The optimized glass/ITO/PEDOT:PSS/PVK//CdSe/ZnS//ZnO-OA/ZnO/Ag QLEDs enhances the maximum luminance by 5 similar to 9% and current efficiency by 16 similar to 35% over the QLEDs with a single ZnO QDs ETL, which can be explained in terms of trap-charge limited current (TCLC) and the Fowler-Nordheim (F-N) tunneling conduction mechanism. English MDPI Enhanced Luminance of CdSe/ZnS Quantum Dots Light-Emitting Diodes Using ZnO-Oleic Acid/ZnO Quantum Dots Double Electron Transport Layer Article 10.3390/nano12122038 1 Nanomaterials, v.12, no.12 Nanomaterials 12 12 Y scie scopus 000817350000001 Chemistry, Multidisciplinary Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Chemistry Science & Technology - Other Topics Materials Science Physics Article NANOPARTICLES IMPROVEMENT EMISSION QLEDs electron transport layer ZnO-OA QDs double ETL hole blocking