title: Cadmium-free quantum dot light emitting devices: energy-transfer realizing pure blue emission.
abstract: In this study, deep blue, pure electroluminescence (EL) at 441.5 nm from a ZnSe/ZnS quantum dot light-emitting device (QD-LED) is obtained by using poly (4-butylphenyl-diphenyl-amine) (poly-TPD) as the hole-transport layer (HTL) to open up the channel for energy transfer from poly-TPD to QDs. The emission originating from HTL is observed in the QD-LED with N,N'-bis (tolyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine functionalized with two styryl groups (2-TPD) as the HTL due to inefficient energy-transfer from 2-TPD to QDs. The poly-TPD based device exhibits color-saturated blue emission with a narrow spectral bandwidth of full width at half maximum (~17.2 nm). These results explore the operating mechanism of the QD EL and signify a remarkable progress in deep blue QD-LEDs based on environmental-friendly QD materials.
authors.affiliation: State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
authors.forename: Wenyu
authors.initials: W
authors.lastname: Ji
authors.forename: Pengtao
authors.initials: P
authors.lastname: Jing
authors.forename: Yi
authors.initials: Y
authors.lastname: Fan
authors.forename: Jialong
authors.initials: J
authors.lastname: Zhao
authors.forename: Yunjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Xianggui
authors.initials: X
authors.lastname: Kong