High-performance crosslinked colloidal quantum-dot light-emitting diodes

• Published in: Nature photonics Vol. 3; no. 6; pp. 341 - 345
• Main Authors: Choi, Byoung Lyong, Cho, Kyung-Sang, Lee, Eun Kyung, Joo, Won-Jae, Jang, Eunjoo, Kim, Tae-Ho, Lee, Sang Jin, Kwon, Soon-Jae, Han, Jai Yong, Kim, Byung-Ki, Kim, Jong Min
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.06.2009; Nature Publishing Group
• Subjects: Applied and Technical Physics; Applied sciences; Electronics; Exact sciences and technology; Fabrication; Injection; Optoelectronic devices; Physics; Physics and Astronomy; Quantum Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Titanium dioxide; Binary compound; Lifetime; Quantum dot; Display devices; Sol gel process; Visible radiation; Red light; Electron transport; Light emitting diode; Titanium Oxides
• ISSN: 1749-4885; 1749-4893
• DOI: 10.1038/nphoton.2009.92

Colloidal quantum-dot light-emitting diodes have recently received considerable attention due to their ease of colour tunability, high brightness and narrow emission bandwidth. Although there have been rapid advances in luminance, efficiency and lifetime, device performance is still limited by the large energy barriers for hole and electron injection into the quantum-dot layer. Here, we show that by crosslinking the colloidal quantum-dot layer, the charge injection barrier in a red-light-emitting quantum-dot light-emitting diode may be considerably reduced by using a sol–gel TiO 2 layer for electron transport. The device architecture is compatible with all-solution device fabrication and the resulting device shows a high luminance (12,380 cd m −2 ), low turn-on voltage (1.9 V) and high power efficiency (2.41 lm W −1 ). Incorporation of the technology into a display device with an active matrix drive backplane suggests that the approach has promise for use in high-performance, easy-to-fabricate, large-area displays and illumination sources. Bright, efficient and low-drive-voltage colloidal quantum-dot LEDs that have a crosslinked-polymer quantum-dot layer, and use a sol–gel titanium oxide layer for electron transport, are reported. Integrating the QD-LEDs with a silicon thin-film transistor backplane results in a QD-LED display.