Park, Young Ran Kim, Hong Hee Eom, Sangwon Choi, Won Kook Choi, Hyosung Lee, Bo Ram Kang, Youngjong 2024-01-19T15:04:43Z 2024-01-19T15:04:43Z 2022-01-25 2021-03 2050-7526 https://pubs.kist.re.kr/handle/201004/117290 Efficiency roll-off is a significant issue in blue light-emitting diodes (LEDs), but its origin still remains controversial. We report CsPbBr3-xClx/PbBry (or PbCly) (core/shell) quantum dot LEDs exhibiting the emission peak spanning from lambda(peak) = 492 to lambda(peak) = 435 nm by varying the Cl composition (0 <= x <= 2.21). PLQY and EQE significantly decreased with the increase of the Cl composition. Careful analyses of the composition and the energy structure using EL, PL, TRPL, UPS, XPS and STEM-EDX measurements reveal that the luminance efficiency roll-off in CsPbBr3-xClx LEDs is attributed to the following three combined effects: (1) luminescence quenching by the non-radiative trap-assisted recombination, (2) the hole transfer process at the CsPbBr3-xClx/PbBry core/shell, and (3) imbalanced charge injection caused by a high energy barrier for the hole conduction at the PVK/QD heterointerface (Delta h &apos;). English ROYAL SOC CHEMISTRY Luminance efficiency roll-off mechanism in CsPbBr3-xClx mixed-halide perovskite quantum dot blue light-emitting diodes Article 10.1039/d0tc05514j 1 JOURNAL OF MATERIALS CHEMISTRY C, v.9, no.10, pp.3608 - 3619 JOURNAL OF MATERIALS CHEMISTRY C 9 10 3608 3619 N scie scopus 000631347900026 2-s2.0-85102931106 Materials Science, Multidisciplinary Physics, Applied Materials Science Physics Article