Morphology of contact printed colloidal quantum dots in organic semiconductor films: Implications for QD-LEDs

Publication Type:

Journal Article

Source:

Phys. Status Solidi C, WILEY-VCH Verlag, Volume 8, Issue 1, p.120-123 (2011)

ISBN:

1862-6351

Keywords:

2011, 2013 and earlier, Electroluminescence, energy-transfer, monolayers, morphology, nanocrystals

Abstract:

Quantum dot light emitting devices (QD-LEDs) con-sist of a monolayer of QDs sandwiched between a hole transporting layer (HTL) and electron
transporting layer (ETL) of organic materials. These hybrid devices emit
with the narrow bandwidth characteristic of the QDs. The precise position
of the QD layer, relative to the interface between the ETL and HTL, can
affect the quantum efficiency of the device on the scale of 10 nm or less.
Motivated by this observation, the exact nature of the morphology of
contact printed and self-assembled QDs on typical organic materials is
investigated. The QDs are substantially pressed into the organic material,
to a somewhat greater extent when contact printed compared to
self-assembled structures. Measured device characteristics from samples
made with the two methods are consistent with these observations (© 2011
WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)