title: Efficient and bright colloidal quantum dot light-emitting diodes via controlling the shell thickness of quantum dots.
abstract: In this paper, we use a simple device architecture based on solution-processed ZnO nanoparticles (NPs) as the electron injection/transport layer and bilayer structure of poly(ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)/poly[9,9-dioctylfluorene-co-N-[4-(3-methylpropyl)]-diphenylamine] (TFB) as the hole injection/transport layer to assess the effect of shell thickness on the properties of quantum-dot-based light emitting diodes (QD-LEDs), comprising CdSe/CdS/ZnS core-shell QDs as the emitting layer. QDs with varying shell thickness were assessed to determine the best option of shell thickness, and the best improvement in device performance was observed when the shell thickness was 2.1 nm. Thereafter, different emissions of QDs, but with optimized same shell thickness (∼2.1 nm), were selected as emitters to be fabricated into same structured QD-LEDs. Highly bright orange-red and green QD-LEDs with peak luminances up to ∼30 000 and ∼52 000 cd m(-2), and power efficiencies of 16 and 19.7 lm W(-1), respectively, were demonstrated successfully. These results may demonstrate a striking basic prototype for the commercialization of QD-based displays and solid-state lightings.
authors.affiliation: Key Laboratory for Special Functional Materials, Henan University , Kaifeng 475004, P. R. China.
authors.forename: Huaibin
authors.initials: H
authors.lastname: Shen
authors.forename: Qinli
authors.initials: Q
authors.lastname: Lin
authors.forename: Hongzhe
authors.initials: H
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Qian
authors.forename: Yixing
authors.initials: Y
authors.lastname: Yang
authors.forename: Alexandre
authors.initials: A
authors.lastname: Titov
authors.forename: Jake
authors.initials: J
authors.lastname: Hyvonen
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
authors.forename: Lin Song
authors.initials: LS
authors.lastname: Li