posted on 2020-02-24, 17:33authored byDonghyo Hahm, Jisoo Park, Inho Jeong, Seunghyun Rhee, Taesoo Lee, Changhee Lee, Seunjun Chung, Wan Ki Bae, Seonwoo Lee
The rising demand
for eradicating hazardous substances
in the workplace has motivated vigorous researches on environmentally
sustainable manufacturing processes of colloidal quantum dots (QDs)
for their optoelectronic applications. Despite remarkable achievements
witnessed in QD materials (e.g., Pb- or Cd-free QDs), the progress
in the eco-friendly process is far falling behind and thus the practical
use of QDs. Herein, a complete “green” process of QDs,
which excludes environmentally unfriendly elements from QDs, ligands,
or solvents, is presented. The implant of mono-2-(methacryloyloxy)ethyl
succinate (MMES) ligands renders InP/ZnSexS1–x QDs dispersed in eco-friendly
polar solvents that are widely accepted in the industry while keeping
the photophysical properties of QDs unchanged. The MMES-capped QDs
show exceptional colloidal stabilities in a range of green polar solvents
that permit uniform inkjet printing of QD dispersion. In addition,
MMES-capped QDs are also compatible with commercially available photo-patternable
resins, and the cross-linkable moiety within MMES further facilitates
the achievement in the formation of well-defined, micrometer-scale
patterning of QD optical films. The presented materials, all composed
of simple, scalable, and environmentally safe compounds, promise low
environmental impact during the processing of QDs and thus will catalyze
the practicable use of QDs in a variety of optoelectronic devices.