Department of Physics; Institute of Advanced Material
Full-solution processed inverted quantum dot light-emitting diodes (QD-LEDs) are promising candidates for application in next generation active matrix displays, due to their low-cost solution fabrication processes and easy integration with n-type thin-film transistor backplanes. In this work, we report high performing transparent inverted QD-LEDs using a full-solution processable hybrid composite anode, formulated using poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS), solution-processed molybdenum trioxide (s-MoO3), and silver nanowires. The effect of the aqueous s-MoO3 additive in PEDOT: PSS anode on efficient operation of the QD-LEDs was systematically investigated. Our results show that the s-MoO3 additive not only enhances the wettability of PEDOT:PSS surface, but also improves the conductivity of the PEDOT:PSS layer, leading to an ohmic contact between the composite anode and hole transporting layer for efficient hole injection. With an optimal s-MoO3 addition in PEDOT:PSS anode, the full-solution processable inverted QD-LEDs with a maximum current efficiency of 1.39 cd/A and a visible light transparency over 70% were demonstrated. The composite transparent anode enables a 27% increase in current efficiency of the full-solution processable QD-LEDs as compared to that of the structurally identical control device without s-MoO3 additive. The encouraging results suggest that our investigation paves a way for the development of efficient vacuum-free transparent inverted QD-LEDs.
full-solution processed composite anode, inverted QD-LEDs, ohmic contact, conductivity, charge transfer, oxidation doping
Source Publication Title
Journal of Materials Chemistry C
Royal Society of Chemistry
© Royal Society of Chemistry 2017
This work was financially supported by the Research Grants Council of Hong Kong Special Administrative Region, China, General Research Fund (GRF/12303114, 12302817), Interinstitutional Collaborative Research Scheme (RC-ICRS/15-16/04) and Shenzhen Peacock Plan (KQTD20140630110339343).
Link to Publisher's Edition
Lee, M., Chen, L., Li, N., & Zhu, F. (2017). MoO3-induced oxidation doping of PEDOT:PSS for high performing full-solution-processed inverted quantum-dot light emitting diodes. Journal of Materials Chemistry C, 5 (40), 10555-10561. https://doi.org/10.1039/C7TC03700G