基于大尺寸量子阱结构的多激子复合动力学  

Multiexcitons Recombination Dynamics Based on Large-scale Quantum Well Structure

作　　者：孟竹 徐豪 MENG Zhu;XU Hao(School of Science,Shenyang Ligong University,Shenyang 110158,China;Institute of Innovation Science and Technology,Shenyang University,Shenyang 110003,China)

机构地区：[1]沈阳理工大学理学院,辽宁沈阳110158 [2]沈阳大学科技创新研究院,辽宁沈阳110003

出　　处：《发光学报》2023年第6期1051-1058,共8页Chinese Journal of Luminescence

基　　金：沈阳理工大学引进高层次人才科研支持经费(1010147001134)。

摘　　要：半导体纳米晶的多激子复合过程在激光器件、发光二极管和光伏等方面具有巨大的应用价值,但粒子体积的减小会加速多激子态的非辐射俄歇复合,这极大地阻碍了相关应用的发展。因此,抑制俄歇复合成为纳米晶体领域一个重要的研究课题。本文基于球形量子阱结构CdS/CdSe/CdS,通过共格应变减小由材料间晶格失配引起的缺陷,制备出高荧光量子产率的大尺寸纳米晶。应用时间分辨荧光光谱技术,在光谱学以及动力学领域研究了大尺寸量子阱的多激子复合特性,分析了单激子及多激子的衰减寿命和谱线特征,并证实了大尺寸量子阱对俄歇复合的抑制作用。本研究有望促进纳米结构在多激子应用中的发展。Colloidal semiconductor nanocrystals present unique electronic and optical properties.The multiexcitons recombination process of semiconductor nanocrystals has attracted extensive attention motivated by the needs of prospective applications in lasing devices,light-emitting diodes,and photovoltaic cells.However,the reduction of particle size will accelerate the non-radiative Auger recombination of multiexcitons states,which significantly hinders the development of related applications.Therefore,suppressing Auger recombination has become an important research topic in the nanocrystal field.Increasing the volume of nanocrystals is considered to be an effective means to decrease Auger recombination.Here,we have synthesized a spherical quantum well structure CdS/CdSe/CdS by hot injection method.As a result of coherent strain,this sandwich like structure can diminish the strain on the interface which is caused by the material lattice mismatch,thus reducing dislocation defects and fabricating large-scale nanocrystals with quantum yield over 80%.By using time-resolved fluorescence spectroscopy,the multiexcitons recombination characteristics of large-scale quantum well are investigated in the fields of spectroscopy and dynamics.The decay lifetime and spectral characteristics of single exciton,biexcitons and high-order multiexcitons are analyzed,and the suppression effect on Auger non-radiative recombination of large-scale quantum well is confirmed.The study of multiexcitons recombination and Auger process in large-scale quantum well is expected to promote the development of nanostructures in multiexcitons applications.

关 键 词：大尺寸量子阱 多激子 时间分辨荧光光谱技术 非辐射复合 

分 类 号：O482.31[理学—固体物理]