Efficient CdSe/CdS quantum dot light-emitting diodes using a thermally polymerized hole transport layer.
We report multilayer nanocrystal quantum dot light-emitting diodes (QD-LEDs) fabricated by spin-coating a monolayer of colloidal CdSe/CdS nanocrystals on top of thermally polymerized solvent-resistant hole-transport layers (HTLs). We obtain high-quality QD layers of controlled thickness (down to submonolayer) simply by spin-coating QD solutions directly onto the HTL. The resulting QD-LEDs exhibit narrow ( approximately 30 nm, fwhm) electroluminescence from the QDs with virtually no emission from the organic matrix at any voltage. Using multiple spin-on HTLs improves the external quantum efficiency of the QD-LEDs to approximately 0.8% at a brightness of 100 cd/m(2) (with a maximum brightness over 1,000 cd/m(2)). We conclude that QD-LEDs could be made more efficient by further optimization of the organic semiconductors.
Zhao
Jialong
J
Department of Chemistry, University of Washington, Box 351700, Seattle, 98195-1700, USA.
Bardecker
Julie A
JA
Munro
Andrea M
AM
Liu
Michelle S
MS
Niu
Yuhua
Y
Ding
I-Kang
IK
Luo
Jingdong
J
Chen
Baoquan
B
Jen
Alex K-Y
AK
Ginger
David S
DS