posted on 2024-11-04, 14:11authored byHuanan Yu, Kaige Zhang, Qiqi Yu, Jingji Zhang, Yongchun Ye, Carl Redshaw, Zhonghui Chen, Dongdong Xu, Georg H. Mehl
Circularly polarized luminescent (CPL) materials have
garnered
considerable interest for a variety of advanced optical applications
including 3D imaging, data encryption, and asymmetric catalysis. However,
the development of high-performance CPL has been hindered by the absence
of simple synthetic methods for chiral luminescent emitters that exhibit
both high quantum yields and dissymmetry factors. In this study, we
present an innovative approach for the synthesis of macro-chiral liquid
crystal quantum dots (Ch-QDs/LC) and their CPL performance enhancement
through doping with 4-cyano-4′-pentylbiphenyl (5CB), thus yielding
a CPL-emitting generator (CEG). The Ch-QDs/LCs were synthesized, and
their surfaces functionalized with a chiral mesogenic ligand, specifically
cholesteryl benzoate, anchored via a lipoic acid linker. Under the
regulation of chiral 2S–Zn2+ coordination complexes,
the chiral LC encapsulation process promotes coordinated ligand substitution,
resulting in an exceptional quantum yield of 56.3%. This is accompanied
by high absorption dissymmetry factor (gabs) and luminescence dissymmetry factor (glum) values ranging from 10–3 to 10–2, surpassing most reported dissymmetry factors by at least an order
of magnitude. The modular Ch-QDs/LCs demonstrate the ability to transfer
chirality to the surrounding medium efficiently and manifest macro-chiral
characteristics within a nematic LC matrix. Utilizing Ch-QDs/LC as
an effective CPL emitter within achiral 5CB matrices enabled the system
to achieve a maximum glum value of 0.35.
The resultant CEG device acted as a direct CPL source, initiating
enantioselective photopolymerization.