title: Heterogeneous stacking of nanodot monolayers by dry pick-and-place transfer and its applications in quantum dot light-emitting diodes.
abstract: Layered assembly structures composed of nanomaterials, such as nanocrystals, have attracted considerable attention as promising candidates for new functional devices whose optical, electromagnetic and electronic behaviours are determined by the spatial arrangement of component elements. However, difficulties in handling each constituent layer in a material-specific manner limit the 3D integration of disparate nanomaterials into the appropriate heterogeneous electronics. Here we report a pick-and-place transfer method that enables the transfer of large-area nanodot assemblies. This solvent-free transfer utilizes a lifting layer and allows for the reliable transfer of a quantum dot (QD) monolayer, enabling layer-by-layer design. With the controlled multistacking of different bandgap QD layers, we are able to probe the interlayer energy transfer among different QD monolayers. By controlling the emission spectrum through such designed monolayer stacking, we have achieved white emission with stable optoelectronic properties, the closest to pure white among the QD light-emitting diodes reported so far.
authors.affiliation: Frontier Research Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics, Yongin, Kyunggi-do 446-712, South Korea.
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Kim
authors.forename: Dae-Young
authors.initials: DY
authors.lastname: Chung
authors.forename: JiYeon
authors.initials: J
authors.lastname: Ku
authors.forename: Inyong
authors.initials: I
authors.lastname: Song
authors.forename: Soohwan
authors.initials: S
authors.lastname: Sul
authors.forename: Dae-Hyeong
authors.initials: DH
authors.lastname: Kim
authors.forename: Kyung-Sang
authors.initials: KS
authors.lastname: Cho
authors.forename: Byoung Lyong
authors.initials: BL
authors.lastname: Choi
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Hwang
authors.forename: Kinam
authors.initials: K
authors.lastname: Kim