Details

Autor(en) / Beteiligte

• Liu, Zhen-Ya
• Liu, An-An
• Fu, Haohao
• Cheng, Qing-Yuan
• Zhang, Ming-Yu
• Pan, Man-Man
• Liu, Li-Ping
• Luo, Meng-Yao
• Tang, Bo
• Zhao, Wei
• Kong, Juan
• Shao, Xueguang
• Pang, Dai-Wen

Titel

Breaking through the Size Control Dilemma of Silver Chalcogenide Quantum Dots via Trialkylphosphine-Induced Ripening: Leading to Ag 2 Te Emitting from 950 to 2100 nm

Ist Teil von

• Journal of the American Chemical Society, 2021-08, Vol.143 (32), p.12867-12877

Ort / Verlag

United States

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Ag Te is one of the most promising semiconductors with a narrow band gap and low toxicity; however, it remains a challenge to tune the emission of Ag Te quantum dots (QDs) precisely and continuously in a wide range. Herein, Ag Te QDs emitting from 950 to 2100 nm have been synthesized via trialkylphosphine-controlled growth. Trialkylphosphine has been found to induce the dissolution of small-sized Ag Te QDs due to its stronger ability to coordinate to the Ag ion than that of 1-octanethiol, predicated by the density functional theory. By controlling this dissolution effect, the monomer supply kinetics can be regulated, achieving precise size control of Ag Te QDs. This synthetic strategy results in state-of-the-art silver-based QDs with emission tunability. Only by taking advantage of such an ultrawide emission has the sizing curve of Ag Te been obtained. Moreover, the absolute photoluminescence quantum yield of Ag Te QDs can reach 12.0% due to their well-passivated Ag-enriched surface with a density of 5.0 ligands/nm , facilitating noninvasive fluorescence imaging. The high brightness in the long-wavelength near-infrared (NIR) region makes the cerebral vasculature and the tiny vessel with a width of only 60 μm clearly discriminable. This work reveals a nonclassical growth mechanism of Ag Te QDs, providing new insight into precisely controlling the size and corresponding photoluminescence properties of semiconductor nanocrystals. The ultrasmall, low-toxicity, emission-tunable, and bright NIR-II Ag Te QDs synthesized in this work offer a tremendous promise for multicolor and deep-tissue fluorescence imaging.