Abstract
Colloidal ZnO nanoparticle (NP) films are recognized as efficient electron transport layers (ETLs) for quantum dot light-emitting diodes (QD-LEDs) with good stability and high efficiency. However, because of the inherently high work function of such films, spontaneous charge transfer occurs at the QD/ZnO interface in such a QD-LED, thus leading to reduced performance. Here, to improve the QD-LED performance, we prepared Ga-doped ZnO NPs with low work functions and tailored band structures via a room-temperature (RT) solution process without the use of bulky organic ligands. We found that the charge transfer at the interface between the CdSe/ZnS QDs and the doped ZnO NPs was significantly weakened because of the incorporated Ga dopants. Remarkably, the as-assembled QD-LEDs, with Ga-doped ZnO NPs as the ETLs, exhibited superior luminances of up to 44 000 cd/m2 and efficiencies of up to 15 cd/A, placing them among the most efficient red-light QD-LEDs ever reported. This discovery provides a new strategy for fabricating high-performance QD-LEDs by using RT-processed Ga-doped ZnO NPs as the ETLs, which could be generalized to improve the efficiency of other optoelectronic devices.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 15605-15614 |
| Number of pages | 10 |
| Journal | ACS Applied Materials & Interfaces |
| Volume | 9 |
| Issue number | 18 |
| DOIs | |
| State | Published - May 2017 |
Bibliographical note
KAUST Repository Item: Exported on 2020-10-01Acknowledgements: This work was financially supported by the National Natural Science Foundation of China (NSFC, Grant No. 61106066), Zhejiang Provincial Science Foundation (Grant No. LY14F040001), Foundation of Educational Commission in Zhejiang Province of China (Grant No. Y201533502), and Natural Science Foundation of Ningbo Municipal Government (Grant Nos. 2016A610104 and 2016A610108).