Ovchinnikov Oleg V, Aslanov Sergey V, Smirnov Mikhail S, Grevtseva Irina G, Perepelitsa Aleksey S
Department of Optics and Spectroscopy, Voronezh State University Voronezh Russia
Voronezh State University of Engineering Technologies Voronezh Russia.
RSC Adv. 2019 Nov 14;9(64):37312-37320. doi: 10.1039/c9ra07047h. eCollection 2019 Nov 13.
In this paper, we present the results on photoinduced formation of colloidal AgS quantum dots with sizes of 1.5-3 nm passivated by 2-mercaptopropionic acid (AgS/2-MPA) in the presence of ethylene glycol. The synthetized colloidal AgS/2-MPA QDs have NIR recombination luminescence with its maximum near 800 nm. The control of absorption and luminescence properties of the QDs is achieved by photoactivation. It is shown that photoexposure of colloidal solution of AgS/2-MPA QDs leads to an increase in the QD size and monodispersity along side with the growth of the luminescence quantum yield from 1% to 7.9%. Enhancement of the luminescence quantum yield is accompanied by an increase in the average luminescence lifetime up to 190 ns, which is due to the blocking of the nonradiative recombination channel with the radiative recombination rate being (3-5.5) × 10 s. It is shown that the purification of the AgS/2-MPA solution by a dialysis membrane from regenerated cellulose leads to an increase in the sample monodispersity, as well as stops the photoinduced growth of QDs, and also reduces the degradation of their photoluminescence.
在本文中，我们展示了在乙二醇存在的情况下，通过光诱导形成尺寸为1.5 - 3纳米、被2 - 巯基丙酸钝化的胶体硫化银量子点（AgS/2 - MPA）的结果。合成的胶体AgS/2 - MPA量子点具有近红外复合发光，其最大值接近800纳米。通过光活化实现了对量子点吸收和发光特性的控制。结果表明，对AgS/2 - MPA量子点胶体溶液进行光照射会导致量子点尺寸增大和单分散性提高，同时发光量子产率从1%增长到7.9%。发光量子产率的提高伴随着平均发光寿命增加至190纳秒，这是由于非辐射复合通道被阻断，辐射复合速率为(3 - 5.5)×10⁸ s⁻¹。结果表明，用再生纤维素透析膜对AgS/2 - MPA溶液进行纯化会导致样品单分散性增加，同时停止量子点的光诱导生长，并减少其光致发光的降解。
