Ultrafast carrier dynamics and third-order nonlinear optical properties of AgInS2/ZnS nanocrystals
Ultrafast carrier dynamics and third-order nonlinear optical properties of AgInS2/ZnS nanocrystals
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AgInS2/ZnS纳米晶的超快载流子动力学和三阶非线性光学性质
DOI：
10.1088/1361-6528/aabab7
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发表时间：
2018
期刊：
影响因子：
3.5
通讯作者：
Tang XS
中科院分区：
文献类型：
--
作者：
Yu Kuai;Yang Yang;Wang Junzhong;Wang Guo Ping;Tang Xiaosheng;Xu Qing-Hua;Wang GP;Tang XS
宽的光致发光（PL）发射、大的Stokes位移和极长的辐射寿命是三元I-III-VI族半导体纳米晶体（NC）的特征，例如CuInS 2和AgInS 2。然而，对它们的发光机理和光生载流子动力学的认识不足限制了它们的进一步应用。本文采用化学方法合成了AgInS 2和AgInS 2/ZnS纳米粒子，并利用时间分辨光致发光谱研究了它们的载流子动力学。结果表明，ZnS合金化有效地钝化了对非辐射衰变过程起主导作用的表面缺陷态。飞秒瞬态吸收光谱也被用来研究载流子动力学，揭示了电子存储在表面态和施主态。此外，利用开孔Z扫描技术测量了AgInS 2和AgInS 2/ZnS纳米晶体的双光子吸收特性。改进的三阶非线性极化率
Broad photoluminescence (PL) emission, a large Stokes shift and extremely long-lived radiative lifetimes are the characteristics of ternary I–III–VI semiconductor nanocrystals (NCs), such as CuInS 2 and AgInS 2. However, the lack of understanding regarding the intriguing PL mechanisms and photo-carrier dynamics limits their further applications. Here, AgInS 2 and AgInS 2/ZnS NCs were chemically synthesized and their carrier dynamics were studied by time-resolved PL spectroscopy. The results demonstrated that the surface defect state, which contributed dominantly to the non-radiative decay processes, was effectively passivated through ZnS alloying. Femtosecond transient absorption spectroscopy was also used to investigate the carrier dynamics, revealing the electron storage at the surface state and donor state. Furthermore, the two photon absorption properties of AgInS 2 and AgInS 2/ZnS NCs were measured using an open-aperture Z-scan technique. The improved third-order nonlinear susceptibility