posted on 2024-01-17, 14:14authored byYuan Qie, Hailong Hu, Kuibao Yu, Chao Zhong, Songman Ju, Yanbing Liu, Tailiang Guo, Fushan Li
The photolithographic patterning of fine quantum dot
(QD) films
is of great significance for the construction of QD optoelectronic
device arrays. However, the photolithography methods reported so far
either introduce insulating photoresist or manipulate the surface
ligands of QDs, each of which has negative effects on device performance.
Here, we report a direct photolithography strategy without photoresist
and without engineering the QD surface ligands. Through cross-linking
of the surrounding semiconductor polymer, QDs are spatially confined
to the network frame of the polymer to form high-quality patterns.
More importantly, the wrapped polymer incidentally regulates the energy
levels of the emitting layer, which is conducive to improving the
hole injection capacity while weakening the electron injection level,
to achieve balanced injection of carriers. The patterned QD light-emitting
diodes (with a pixel size of 1.5 μm) achieve a high external
quantum efficiency of 16.25% and a brightness of >1.4 × 105 cd/m2. This work paves the way for efficient high-resolution
QD light-emitting devices.