Sky Blue and Yellow Cluster Light-Emitting Diodes Based on Asymmetric Cu4I4 Nanocubes
Nan Zhang,
Lei Qu,
Huan Hu,
Ran Huo,
Yushan Meng,
Chunbo Duan,
Jing Zhang,
Chunmiao Han,
Guohua Xie,
Hui Xu
Affiliations
Nan Zhang
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Lei Qu
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Huan Hu
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Ran Huo
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Yushan Meng
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Chunbo Duan
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Jing Zhang
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Chunmiao Han
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Guohua Xie
Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, P. R. China.
Hui Xu
Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Material Science, Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
Controllably optimizing excited-state characteristics is crucial for luminescent nanoclusters but remains a formidable challenge. Herein, we report an effective “ligand-induced asymmetrization” strategy for constructing thermally activated delayed fluorescence-featured cubic Cu4I4 nanoclusters with asymmetric configurations, named [tBCzDBFDP]2Cu4I4 and [PTZDBFDP]2Cu4I4. Through changing 3,6-di-tert-butyl-carbazole (tBCz) to phenothiazine (PTZ) with a stronger electron-donating effect, emission color is tuned from greenish blue of [tBCzDBFDP]2Cu4I4 to yellow of [PTZDBFDP]2Cu4I4, as well as the triplet locally excited state of the former to the triplet charge transfer state of the latter. Temperature-correlated spectroscopic investigation indicates that in terms of triplet quenching suppression, [tBCzDBFDP]2Cu4I4 is superior to [PTZDBFDP]2Cu4I4, in accord with the stabilities of their triplet locally excited state and triplet charge transfer state. As a consequence, these asymmetric Cu4I4 nanocubes endowed their cluster light-emitting diodes with the external quantum efficiencies beyond 12% for sky blue and 8% for yellow. These results suggest the significance and effectiveness of ligand engineering for optoelectronic nanoclusters.
