We fabricated the colloidal quantum-dot light-emitting diodes (QDLEDs) with the HfO2/SiO2-distributed Bragg reflector (DBR) structure using a pulsed spray coating method. Moreover, pixelated RGB arrays, 2-in. wafer-scale white light emission, and an integrated small footprint white light device were demonstrated. The experimental results showed that the intensity of red, blue, and green (RGB) emissions exhibited considerable enhancement because of the high reflectivity in the UV region by the DBR structure, which subsequently increased the use in the UV optical pumping of RGB QDs. In this experiment, a pulsed spray coating method was crucial in providing uniform RGB layers, and the polydimethylsiloxane (PDMS) film was used as the interface layer between each RGB color to avoid crosscontamination and self-assembly of QDs. Furthermore, the chromaticity coordinates of QDLEDs with the DBR structure remained constant under various pumping powers in the large area sample, whereas a larger shift toward high color temperatures was observed in the integrated device. The resulting color gamut of the proposed QDLEDs covered an area 1.2 times larger than that of the NTSC standard, which is favorable for the next generation of high-quality display technology.

Date Published: 4 March 2013
PDF: 6 pages
Proc. SPIE 8641, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XVII, 864121 (4 March 2013); doi: 10.1117/12.2004101

Published in SPIE Proceedings Vol. 8641:
Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XVII
Klaus P. Streubel; Heonsu Jeon; Li-Wei Tu; Martin Strassburg, Editor(s)