title: Solid Solution Quantum Dots with Tunable Dual or Ultrabroadband Emission for LEDs.
abstract: Quantum dots that efficiently emit white light directly or feature a "candle-like" orange photoluminescence with a high Stokes shift are presented. The key to obtaining these unique emission properties is through controlled annealing of the core Cu-In-Ga-S quantum dots in the presence of zinc ions, thus forming Zn-Cu-In-Ga-S solid solutions with different distributions of the substitution and dopant elements. The as-obtained nanocrystals feature excellent quantum yields of up to 82% with limited or even eliminated reabsorption and a color rendering index of bare particles of up to 88, enabling the production of high-quality white LEDs using a single color converter layer. Furthermore, the color properties can be tuned by changing the experimental conditions as well as by varying the excitation wavelength. The multicomponent luminescence mechanism is discussed in detail based on similar literature reports. White LEDs with unparalleled color quality and competitive luminous efficacies are presented herein.
authors.affiliation: Department of Chemical Engineering, Münster University of Applied Sciences , Stegerwaldstraße 39, 48565 Steinfurt, Germany.|Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster , Corrensstraße 30, 48149 Münster, Germany.
authors.forename: Krzysztof
authors.identifier: http://orcid.org/0000-0001-5099-438X
authors.initials: K
authors.lastname: Gugula
authors.affiliation: Physikalisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 10, 48149 Münster, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Entrup
authors.affiliation: Physikalisches Institut and Center for Nanotechnology, Westfälische Wilhelms-Universität Münster , Heisenbergstraße 11, 48149 Münster, Germany.
authors.forename: Linda
authors.initials: L
authors.lastname: Stegemann
authors.affiliation: Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster , Corrensstraße 30, 48149 Münster, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Seidel
authors.affiliation: Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster , Corrensstraße 30, 48149 Münster, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Pöttgen
authors.affiliation: Physikalisches Institut and Center for Nanotechnology, Westfälische Wilhelms-Universität Münster , Heisenbergstraße 11, 48149 Münster, Germany.
authors.forename: Cristian A
authors.initials: CA
authors.lastname: Strassert
authors.affiliation: Department of Chemical Engineering, Münster University of Applied Sciences , Stegerwaldstraße 39, 48565 Steinfurt, Germany.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0001-5024-2356
authors.initials: M
authors.lastname: Bredol
keywords: alloyed quantum dots; codoped; color converter; defect chemistry; high Stokes shift