Laser-annealing-made amplified spontaneous emission of "giant" CdSe/CdS core/shell nanocrystals transferred from bulk-like shell to quantum-confined core

作     者：Chen Liao Kai Fan Ruilin Xu Huichao Zhang Changgui Lu Yiping Cui Jiayu Zhang 

作者机构：Advanced Photonic Center Southeast University 

出 版 物：《Photonics Research》 (光子学研究（英文版）)

年 卷 期：2015年第3卷第5期

页      面：200-205页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：supported by the National Basic Research Program of China (973 Program, 2012CB921801) the Science and Technology Department of Jiang Su Province (BE2012163) the Scientific Research Foundation of Graduate School of Southeast University (YBJJ1443) 

主　　题：core Laser-annealing-made amplified spontaneous emission of CdSe/CdS core/shell nanocrystals transferred from bulk-like shell to quantum-confined core giant 

摘      要： Giant Cd Se/Cd S core/shell nanocrystals(NCs) were synthesized with thick Cd S shell(15 monolayers), and the x-ray diffraction(XRD) measurement indicates there is a zinc blende phase in the thick Cd S shell, whereas it transformed into wurtzite phase under 5 min radiation with a 400 nm, 594 μJ∕cm2femtosecond(fs) laser *** evolution of the NCs’ spontaneous emission under the fs laser radiation was recorded with a Hamamatsu streak camera. The as-synthesized NCs exhibit an amplified spontaneous emission(ASE) at 530 nm, which comes from a bulk-like Cd S shell due to the interfacial potential barrier, which could slow down the relaxation of holes from the shell to the core. After being annealed by an fs laser, the ASE of the g-NCs is transferred from a bulk-like Cd S shell to a quantum-confined Cd Se core because the phase transformation determined with the XRD measurement could remove the interfacial barrier. Besides the ASE at 643 nm, two shorter-wavelength ASE peaks at 589 and 541 nm, corresponding to optical transitions of the second(1P) and third(1D) electron quantization shells of the Cd Se core, also appear, thus indicating that Auger recombination is effectively suppressed.