Quantum dot (QD) light-emitting diodes have been intensively investigated as a future display technology owing to their outstanding optoelectronic properties such as narrow spectral bandwidths and high quantum efficiencies. Significant efforts have been made to achieve full color QD light-emitting diodes (QLEDs) by applying various fine-patterning technologies to active QD layers. However, the reported patterning methods generally require high processing cost and complex facilities which have limited their wide adoption in industrial-scale display applications. In this study, a fine patterning method is presented by employing spatial light-assisted and locally controlled surface tailoring. The chemical functionality of an interfacial polyethyleneimine (PEI) layer between ZnO and the QD layers is locally controlled by spatial light patterning (SLP), which is simultaneously used as a charge transfer layer and an anchoring agent for the selected QD nanoparticles. The versatility of this approach is demonstrated by patterning crossed stripes and multicolor QLED devices on selectively patterned PEI layers with a maximum luminescence of 1950 cd m−2 and a current efficiency of 2.9 cd A−1. The SLP process described herein is a general approach for fabricating full color QLEDs with marginal toxicity. This process is compatible with the standard complementary metal-oxide semiconductor (CMOS) processing technology.
Bibliographical noteFunding Information:
This research was supported by the Human Resources Development (No.20174030201810) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy, the Industrial Strategic Technology Development Program [10045145, Development of high performance (>70 cm−2 V−1 s−1) chalcogenide TFT backplane and cadmium-free highly efficient (>30 cd A−1) hybrid EL material/devices] funded by MOTIE/KEIT, and the National Research Foundation of Korea (NRF) funded by the Korea government (No. 2014M3A9B8023478).
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- full color QLEDs
- photochemical reaction
- quantum dots
- quantum-dot light-emitting diodes
- spatial light patterning
- surface tailoring
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics